diff --git a/build.gradle b/build.gradle
index 5cd2de53441..ed1c9359026 100644
--- a/build.gradle
+++ b/build.gradle
@@ -69,6 +69,10 @@ shadowJar {
     archiveFileName = 'addressbook.jar'
 }
 
+run {
+    enableAssertions = true
+}
+
 defaultTasks 'clean', 'test'
 
 run {
diff --git a/src/main/java/seedu/address/logic/Messages.java b/src/main/java/seedu/address/logic/Messages.java
index a9b21234c49..50e2eebf552 100644
--- a/src/main/java/seedu/address/logic/Messages.java
+++ b/src/main/java/seedu/address/logic/Messages.java
@@ -5,6 +5,7 @@
 import java.util.stream.Stream;
 
 import seedu.address.logic.parser.Prefix;
+import seedu.address.model.person.Lead;
 import seedu.address.model.person.Person;
 
 /**
@@ -35,6 +36,10 @@ public static String getErrorMessageForDuplicatePrefixes(Prefix... duplicatePref
      * Formats the {@code person} for display to the user.
      */
     public static String format(Person person) {
+        if (person.isLead()) {
+            return format((Lead) person);
+        }
+        assert(!person.isLead());
         final StringBuilder builder = new StringBuilder();
         builder.append(person.getName())
                 .append("; Phone: ")
@@ -50,4 +55,26 @@ public static String format(Person person) {
         return builder.toString();
     }
 
+    /**
+     * Formats the {@code lead} for display to the user.
+     */
+    public static String format(Lead lead) {
+        assert(lead.isLead());
+        final StringBuilder builder = new StringBuilder();
+        builder.append(lead.getName())
+                .append("; Phone: ")
+                .append(lead.getPhone())
+                .append("; Email: ")
+                .append(lead.getEmail())
+                .append("; Address: ")
+                .append(lead.getAddress())
+                .append("; Key Milestone: ")
+                .append(lead.getKeyMilestone())
+                .append("; Meeting Time: ")
+                .append(lead.getKeyMilestone())
+                .append("; Tags: ");
+        lead.getTags().forEach(builder::append);
+        return builder.toString();
+    }
+
 }
diff --git a/src/main/java/seedu/address/logic/commands/AddLeadCommand.java b/src/main/java/seedu/address/logic/commands/AddLeadCommand.java
index 65165faa77a..355d682ca6f 100644
--- a/src/main/java/seedu/address/logic/commands/AddLeadCommand.java
+++ b/src/main/java/seedu/address/logic/commands/AddLeadCommand.java
@@ -3,6 +3,7 @@
 import static java.util.Objects.requireNonNull;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_ADDRESS;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_EMAIL;
+import static seedu.address.logic.parser.CliSyntax.PREFIX_KEY_MILESTONE;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_MEETING_TIME;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_NAME;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_PHONE;
@@ -27,6 +28,7 @@ public class AddLeadCommand extends Command {
             + PREFIX_PHONE + "PHONE "
             + PREFIX_EMAIL + "EMAIL "
             + PREFIX_ADDRESS + "ADDRESS "
+            + PREFIX_KEY_MILESTONE + "KEY_MILESTONE "
             + PREFIX_MEETING_TIME + "MEETING_TIME "
             + "[" + PREFIX_TAG + "TAG]...\n"
             + "Example: " + COMMAND_WORD + " "
@@ -34,6 +36,7 @@ public class AddLeadCommand extends Command {
             + PREFIX_PHONE + "98765432 "
             + PREFIX_EMAIL + "johnd@example.com "
             + PREFIX_ADDRESS + "311, Clementi Ave 2, #02-25 "
+            + PREFIX_KEY_MILESTONE + "01/12/2023 "
             + PREFIX_MEETING_TIME + "10/10/2023 14:30 "
             + PREFIX_TAG + "classmate";
 
diff --git a/src/main/java/seedu/address/logic/commands/ConvertClientToLeadCommand.java b/src/main/java/seedu/address/logic/commands/ConvertClientToLeadCommand.java
index 9de63f7135d..b712bafc8b6 100644
--- a/src/main/java/seedu/address/logic/commands/ConvertClientToLeadCommand.java
+++ b/src/main/java/seedu/address/logic/commands/ConvertClientToLeadCommand.java
@@ -15,6 +15,7 @@
 import seedu.address.model.person.Address;
 import seedu.address.model.person.Client;
 import seedu.address.model.person.Email;
+import seedu.address.model.person.KeyMilestone;
 import seedu.address.model.person.Lead;
 import seedu.address.model.person.MeetingTime;
 import seedu.address.model.person.Name;
@@ -22,6 +23,7 @@
 import seedu.address.model.person.Phone;
 import seedu.address.model.tag.Tag;
 
+
 /**
  * Converts a Client to a Lead in the address book.
  */
@@ -65,13 +67,15 @@ public CommandResult execute(Model model) throws CommandException {
         Phone phone = personToConvert.getPhone();
         Email email = personToConvert.getEmail();
         Address address = personToConvert.getAddress();
+        //todo: temporary fix for keyMilestone
+        KeyMilestone keyMilestone = null;
         Set<Tag> tags = new HashSet<>(personToConvert.getTags());
         Optional<MeetingTime> meetingTime = personToConvert.getMeetingTime();
 
         // TODO: Add more fields from client to lead
 
 
-        Lead convertedLead = new Lead(name, phone, email, address, meetingTime, tags);
+        Lead convertedLead = new Lead(name, phone, email, address, keyMilestone, meetingTime, tags);
 
         model.setPerson(personToConvert, convertedLead);
         model.updateFilteredPersonList(PREDICATE_SHOW_ALL_PERSONS);
diff --git a/src/main/java/seedu/address/logic/commands/DeleteMeetingCommand.java b/src/main/java/seedu/address/logic/commands/DeleteMeetingCommand.java
new file mode 100644
index 00000000000..cfea0d704a9
--- /dev/null
+++ b/src/main/java/seedu/address/logic/commands/DeleteMeetingCommand.java
@@ -0,0 +1,117 @@
+package seedu.address.logic.commands;
+
+import static java.util.Objects.requireNonNull;
+import static seedu.address.model.Model.PREDICATE_SHOW_ALL_PERSONS;
+
+import java.util.List;
+import java.util.Optional;
+
+import seedu.address.commons.core.index.Index;
+import seedu.address.commons.util.ToStringBuilder;
+import seedu.address.logic.Messages;
+import seedu.address.logic.commands.exceptions.CommandException;
+import seedu.address.model.Model;
+import seedu.address.model.person.Client;
+import seedu.address.model.person.Lead;
+import seedu.address.model.person.Person;
+
+/**
+ * Deletes a meeting identified using it's displayed index from the address book.
+ */
+public class DeleteMeetingCommand extends Command {
+
+    public static final String COMMAND_WORD = "deletemeeting";
+
+    public static final String MESSAGE_USAGE = COMMAND_WORD
+            + ": Deletes the meeting identified by the index number used in the displayed meeting list.\n"
+            + "Parameters: INDEX (must be a positive integer)\n"
+            + "Example: " + COMMAND_WORD + " 1";
+
+    public static final String MESSAGE_DELETE_MEETING_SUCCESS = "Deleted Meeting: %1$s from Person %2$s";
+
+    private final Index targetIndex;
+
+    public DeleteMeetingCommand(Index targetIndex) {
+        this.targetIndex = targetIndex;
+    }
+
+    /**
+     * Deletes the meeting from the person.
+     * @param personToDeleteMeeting Person to delete meeting from.
+     * @return Person with meeting deleted.
+     */
+    private static Person deleteMeeting(Person personToDeleteMeeting) {
+        requireNonNull(personToDeleteMeeting);
+        assert personToDeleteMeeting.isLead() || personToDeleteMeeting.isClient();
+
+        if (personToDeleteMeeting.getMeetingTime().isEmpty()) {
+            return personToDeleteMeeting;
+        }
+
+        Person personWithMeetingDeleted;
+
+        if (personToDeleteMeeting.isClient()) {
+            personWithMeetingDeleted = new Client(
+                personToDeleteMeeting.getName(),
+                personToDeleteMeeting.getPhone(),
+                personToDeleteMeeting.getEmail(),
+                personToDeleteMeeting.getAddress(),
+                Optional.empty(),
+                personToDeleteMeeting.getTags());
+        } else {
+            // If person is not Client, person is a Lead
+            assert personToDeleteMeeting.isLead();
+            Lead leadWithMeetingDeleted = (Lead) personToDeleteMeeting;
+            personWithMeetingDeleted = new Lead(
+                    leadWithMeetingDeleted.getName(),
+                    leadWithMeetingDeleted.getPhone(),
+                    leadWithMeetingDeleted.getEmail(),
+                    leadWithMeetingDeleted.getAddress(),
+                    leadWithMeetingDeleted.getKeyMilestone(),
+                    Optional.empty(),
+                    leadWithMeetingDeleted.getTags());
+        }
+
+        return personWithMeetingDeleted;
+    }
+
+    @Override
+    public CommandResult execute(Model model) throws CommandException {
+        requireNonNull(model);
+        List<Person> lastShownList = model.getFilteredPersonList();
+
+        if (targetIndex.getZeroBased() >= lastShownList.size()) {
+            throw new CommandException(Messages.MESSAGE_INVALID_PERSON_DISPLAYED_INDEX);
+        }
+
+        Person personToDeleteMeeting = lastShownList.get(targetIndex.getZeroBased());
+        Person personWithMeetingDeleted = deleteMeeting(personToDeleteMeeting);
+        model.setPerson(personToDeleteMeeting, personWithMeetingDeleted);
+        model.updateFilteredPersonList(PREDICATE_SHOW_ALL_PERSONS);
+        return new CommandResult(String.format(MESSAGE_DELETE_MEETING_SUCCESS,
+                personToDeleteMeeting.getMeetingTimeString(),
+                targetIndex.getOneBased()));
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        if (other == this) {
+            return true;
+        }
+
+        // instanceof handles nulls
+        if (!(other instanceof DeleteMeetingCommand)) {
+            return false;
+        }
+
+        DeleteMeetingCommand otherDeleteMeetingCommand = (DeleteMeetingCommand) other;
+        return targetIndex.equals(otherDeleteMeetingCommand.targetIndex);
+    }
+
+    @Override
+    public String toString() {
+        return new ToStringBuilder(this)
+                .add("targetIndex", targetIndex)
+                .toString();
+    }
+}
diff --git a/src/main/java/seedu/address/logic/commands/EditCommand.java b/src/main/java/seedu/address/logic/commands/EditCommand.java
index c23384aa3a3..cd7eadde35c 100644
--- a/src/main/java/seedu/address/logic/commands/EditCommand.java
+++ b/src/main/java/seedu/address/logic/commands/EditCommand.java
@@ -25,6 +25,7 @@
 import seedu.address.model.person.Address;
 import seedu.address.model.person.Client;
 import seedu.address.model.person.Email;
+import seedu.address.model.person.KeyMilestone;
 import seedu.address.model.person.Lead;
 import seedu.address.model.person.MeetingTime;
 import seedu.address.model.person.Name;
@@ -32,13 +33,14 @@
 import seedu.address.model.person.Phone;
 import seedu.address.model.tag.Tag;
 
+
+
 /**
  * Edits the details of an existing person in the address book.
  */
 public class EditCommand extends Command {
 
     public static final String COMMAND_WORD = "edit";
-
     public static final String MESSAGE_USAGE = COMMAND_WORD + ": Edits the details of the person identified "
             + "by the index number used in the displayed person list. "
             + "Existing values will be overwritten by the input values.\n"
@@ -54,6 +56,7 @@ public class EditCommand extends Command {
             + PREFIX_EMAIL + "johndoe@example.com";
 
     public static final String MESSAGE_EDIT_PERSON_SUCCESS = "Edited Person: %1$s";
+    public static final String MESSAGE_EDIT_LEAD_SUCCESS = "Edited Lead: %1$s";
     public static final String MESSAGE_NOT_EDITED = "At least one field to edit must be provided.";
     public static final String MESSAGE_DUPLICATE_PERSON = "This person already exists in the address book.";
 
@@ -86,14 +89,18 @@ private static Person createEditedPerson(Person personToEdit, EditPersonDescript
         Optional<MeetingTime> updatedMeetingTime = editPersonDescriptor.getMeetingTime()
                 .or(personToEdit::getMeetingTime);
         Set<Tag> updatedTags = editPersonDescriptor.getTags().orElse(personToEdit.getTags());
-
-        if (personToEdit.isClient()) {
-            return new Client(updatedName, updatedPhone, updatedEmail, updatedAddress, updatedMeetingTime, updatedTags);
-        } else {
-            return new Lead(updatedName, updatedPhone, updatedEmail, updatedAddress, updatedMeetingTime, updatedTags);
+        //todo: this temporary fix related to the one in editcommandparser
+        if (personToEdit.isLead()) {
+            //keyMilestone will not be updated if editLeadCommand is not used
+            Lead leadToEdit = (Lead) personToEdit;
+            KeyMilestone keyMilestone = leadToEdit.getKeyMilestone();
+            return new Lead(updatedName, updatedPhone, updatedEmail, updatedAddress, keyMilestone,
+                    updatedMeetingTime, updatedTags);
         }
+        return new Client(updatedName, updatedPhone, updatedEmail, updatedAddress, updatedMeetingTime, updatedTags);
     }
 
+
     @Override
     public CommandResult execute(Model model) throws CommandException {
         requireNonNull(model);
@@ -166,7 +173,6 @@ public EditPersonDescriptor(EditPersonDescriptor toCopy) {
             setMeetingTime(toCopy.meetingTime);
             setTags(toCopy.tags);
         }
-
         /**
          * Returns true if at least one field is edited.
          */
@@ -263,4 +269,66 @@ public String toString() {
                     .toString();
         }
     }
+
+    /**
+     * Stores the details to edit the lead with. Each non-empty field value will replace the
+     * corresponding field value of the lead.
+     */
+    public static class EditLeadDescriptor extends EditPersonDescriptor {
+        //This class only used for edit KeyMilestone, for other field of leads like name, editPersonDescriptor
+        // will be used
+        private KeyMilestone keyMilestone;
+        /**
+         * Copy constructor only for leads.
+         * A defensive copy of {@code tags} is used internally.
+         */
+        public EditLeadDescriptor(EditLeadDescriptor toCopy) {
+            super(toCopy);
+            setKeyMilestone(toCopy.keyMilestone);
+        }
+
+        public EditLeadDescriptor() {
+
+        }
+
+        @Override
+        public boolean isAnyFieldEdited() {
+            return super.isAnyFieldEdited() || CollectionUtil.isAnyNonNull(keyMilestone);
+        }
+
+        public Optional<KeyMilestone> getKeyMilestone() {
+            return Optional.ofNullable(keyMilestone);
+        }
+
+        public void setKeyMilestone(KeyMilestone keyMilestone) {
+            this.keyMilestone = keyMilestone;
+        }
+
+        @Override
+        public boolean equals(Object other) {
+            if (other == this) {
+                return true;
+            }
+
+            // instanceof handles nulls
+            if (!(other instanceof EditLeadDescriptor)) {
+                return false;
+            }
+            EditLeadDescriptor otherEditLeadDescriptor = (EditLeadDescriptor) other;
+            return super.equals(other) && Objects.equals(keyMilestone, otherEditLeadDescriptor.keyMilestone);
+        }
+
+        @Override
+        public String toString() {
+            return new ToStringBuilder(this)
+                    .add("name", super.name)
+                    .add("phone", super.phone)
+                    .add("email", super.email)
+                    .add("address", super.address)
+                    .add("key milestone", keyMilestone)
+                    .add("meeting time", super.meetingTime)
+                    .add("tags", super.tags)
+                    .toString();
+        }
+    }
 }
diff --git a/src/main/java/seedu/address/logic/commands/EditLeadCommand.java b/src/main/java/seedu/address/logic/commands/EditLeadCommand.java
new file mode 100644
index 00000000000..850af8b3e17
--- /dev/null
+++ b/src/main/java/seedu/address/logic/commands/EditLeadCommand.java
@@ -0,0 +1,135 @@
+package seedu.address.logic.commands;
+
+import static java.util.Objects.requireNonNull;
+import static seedu.address.logic.parser.CliSyntax.PREFIX_ADDRESS;
+import static seedu.address.logic.parser.CliSyntax.PREFIX_EMAIL;
+import static seedu.address.logic.parser.CliSyntax.PREFIX_KEY_MILESTONE;
+import static seedu.address.logic.parser.CliSyntax.PREFIX_MEETING_TIME;
+import static seedu.address.logic.parser.CliSyntax.PREFIX_NAME;
+import static seedu.address.logic.parser.CliSyntax.PREFIX_PHONE;
+import static seedu.address.logic.parser.CliSyntax.PREFIX_TAG;
+import static seedu.address.model.Model.PREDICATE_SHOW_ALL_PERSONS;
+
+import java.util.List;
+import java.util.Optional;
+import java.util.Set;
+
+import seedu.address.commons.core.index.Index;
+import seedu.address.commons.util.ToStringBuilder;
+import seedu.address.logic.Messages;
+import seedu.address.logic.commands.exceptions.CommandException;
+import seedu.address.model.Model;
+import seedu.address.model.person.Address;
+import seedu.address.model.person.Email;
+import seedu.address.model.person.KeyMilestone;
+import seedu.address.model.person.Lead;
+import seedu.address.model.person.MeetingTime;
+import seedu.address.model.person.Name;
+import seedu.address.model.person.Person;
+import seedu.address.model.person.Phone;
+import seedu.address.model.tag.Tag;
+
+/**
+ * Edits the details of an existing lead in the address book.
+ */
+public class EditLeadCommand extends EditCommand {
+
+    public static final String COMMAND_WORD = "edit";
+    public static final String MESSAGE_USAGE = COMMAND_WORD + ": Edits the details of the person identified "
+            + "by the index number used in the displayed person list. "
+            + "Existing values will be overwritten by the input values.\n"
+            + "Parameters: INDEX (must be a positive integer) "
+            + "[" + PREFIX_NAME + "NAME] "
+            + "[" + PREFIX_PHONE + "PHONE] "
+            + "[" + PREFIX_EMAIL + "EMAIL] "
+            + "[" + PREFIX_ADDRESS + "ADDRESS] "
+            + "[" + PREFIX_KEY_MILESTONE + "KEY_MILESTONE] "
+            + "[" + PREFIX_MEETING_TIME + "MEETING_TIME] "
+            + "[" + PREFIX_TAG + "TAG]...\n"
+            + "Example: " + COMMAND_WORD + " 1 "
+            + PREFIX_PHONE + "91234567 "
+            + PREFIX_EMAIL + "johndoe@example.com";
+
+
+    private final Index index;
+    private final EditLeadDescriptor editLeadDescriptor;
+
+    /**
+     * @param index                of the person in the filtered person list to edit
+     * @param editLeadDescriptor details to edit the lead with
+     */
+    public EditLeadCommand(Index index, EditLeadDescriptor editLeadDescriptor) {
+        super(index, editLeadDescriptor);
+        requireNonNull(index);
+        requireNonNull(editLeadDescriptor);
+
+        this.index = index;
+        this.editLeadDescriptor = new EditLeadDescriptor(editLeadDescriptor);
+    }
+
+
+    private static Lead createEditedLead(Lead leadToEdit, EditLeadDescriptor editLeadDescriptor) {
+        assert leadToEdit != null;
+
+        Name updatedName = editLeadDescriptor.getName().orElse(leadToEdit.getName());
+        Phone updatedPhone = editLeadDescriptor.getPhone().orElse(leadToEdit.getPhone());
+        Email updatedEmail = editLeadDescriptor.getEmail().orElse(leadToEdit.getEmail());
+        Address updatedAddress = editLeadDescriptor.getAddress().orElse(leadToEdit.getAddress());
+        Set<Tag> updatedTags = editLeadDescriptor.getTags().orElse(leadToEdit.getTags());
+        KeyMilestone updatedKeyMilestone = editLeadDescriptor.getKeyMilestone()
+                .orElse(leadToEdit.getKeyMilestone());
+        Optional<MeetingTime> updatedMeetingTime = editLeadDescriptor.getMeetingTime()
+                .or(leadToEdit::getMeetingTime);
+
+        return new Lead(updatedName, updatedPhone, updatedEmail, updatedAddress, updatedKeyMilestone,
+                updatedMeetingTime, updatedTags);
+    }
+
+    @Override
+    public CommandResult execute(Model model) throws CommandException {
+        requireNonNull(model);
+        List<Person> lastShownList = model.getFilteredPersonList();
+
+        if (index.getZeroBased() >= lastShownList.size()) {
+            throw new CommandException(Messages.MESSAGE_INVALID_PERSON_DISPLAYED_INDEX);
+        }
+
+        Lead leadToEdit = (Lead) lastShownList.get(index.getZeroBased());
+        assert(leadToEdit.isLead());
+        Lead editedLead = createEditedLead((Lead) leadToEdit, editLeadDescriptor);
+
+        if (!leadToEdit.isSamePerson(editedLead) && model.hasPerson(editedLead)) {
+            throw new CommandException(MESSAGE_DUPLICATE_PERSON);
+        }
+
+        model.setPerson(leadToEdit, editedLead);
+        model.updateFilteredPersonList(PREDICATE_SHOW_ALL_PERSONS);
+        return new CommandResult(String.format(MESSAGE_EDIT_LEAD_SUCCESS, Messages.format(editedLead)));
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        if (other == this) {
+            return true;
+        }
+
+        // instanceof handles nulls
+        if (!(other instanceof EditLeadCommand)) {
+            return false;
+        }
+
+        EditLeadCommand otherEditCommand = (EditLeadCommand) other;
+        return index.equals(otherEditCommand.index)
+                && editLeadDescriptor.equals(otherEditCommand.editLeadDescriptor);
+    }
+
+    @Override
+    public String toString() {
+        return new ToStringBuilder(this)
+                .add("index", index)
+                .add("editLeadDescriptor", editLeadDescriptor)
+                .toString();
+    }
+
+
+}
diff --git a/src/main/java/seedu/address/logic/parser/AddLeadCommandParser.java b/src/main/java/seedu/address/logic/parser/AddLeadCommandParser.java
index 371232c2d36..7006892e032 100644
--- a/src/main/java/seedu/address/logic/parser/AddLeadCommandParser.java
+++ b/src/main/java/seedu/address/logic/parser/AddLeadCommandParser.java
@@ -3,6 +3,7 @@
 import static seedu.address.logic.Messages.MESSAGE_INVALID_COMMAND_FORMAT;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_ADDRESS;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_EMAIL;
+import static seedu.address.logic.parser.CliSyntax.PREFIX_KEY_MILESTONE;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_MEETING_TIME;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_NAME;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_PHONE;
@@ -16,6 +17,7 @@
 import seedu.address.logic.parser.exceptions.ParseException;
 import seedu.address.model.person.Address;
 import seedu.address.model.person.Email;
+import seedu.address.model.person.KeyMilestone;
 import seedu.address.model.person.Lead;
 import seedu.address.model.person.MeetingTime;
 import seedu.address.model.person.Name;
@@ -35,26 +37,28 @@ public class AddLeadCommandParser implements Parser<AddLeadCommand> {
     public AddLeadCommand parse(String args) throws ParseException {
         ArgumentMultimap argMultimap =
                 ArgumentTokenizer.tokenize(args, PREFIX_NAME, PREFIX_PHONE, PREFIX_EMAIL,
-                        PREFIX_ADDRESS, PREFIX_MEETING_TIME, PREFIX_TAG);
+                        PREFIX_ADDRESS, PREFIX_KEY_MILESTONE, PREFIX_MEETING_TIME, PREFIX_TAG);
 
-        if (!arePrefixesPresent(argMultimap, PREFIX_NAME, PREFIX_ADDRESS, PREFIX_PHONE, PREFIX_EMAIL)
+        if (!arePrefixesPresent(argMultimap, PREFIX_NAME, PREFIX_ADDRESS, PREFIX_PHONE, PREFIX_KEY_MILESTONE,
+                 PREFIX_EMAIL)
                 || !argMultimap.getPreamble().isEmpty()) {
             throw new ParseException(String.format(MESSAGE_INVALID_COMMAND_FORMAT, AddLeadCommand.MESSAGE_USAGE));
         }
 
-        argMultimap.verifyNoDuplicatePrefixesFor(PREFIX_NAME, PREFIX_PHONE, PREFIX_EMAIL,
-                PREFIX_ADDRESS, PREFIX_MEETING_TIME);
+        argMultimap.verifyNoDuplicatePrefixesFor(PREFIX_NAME, PREFIX_PHONE, PREFIX_EMAIL, PREFIX_ADDRESS,
+                PREFIX_MEETING_TIME, PREFIX_KEY_MILESTONE);
         Name name = ParserUtil.parseName(argMultimap.getValue(PREFIX_NAME).get());
         Phone phone = ParserUtil.parsePhone(argMultimap.getValue(PREFIX_PHONE).get());
         Email email = ParserUtil.parseEmail(argMultimap.getValue(PREFIX_EMAIL).get());
         Address address = ParserUtil.parseAddress(argMultimap.getValue(PREFIX_ADDRESS).get());
+        KeyMilestone keyMilestone = ParserUtil.parseKeyMilestone(argMultimap.getValue(PREFIX_KEY_MILESTONE).get());
         Optional<MeetingTime> meetingTime = argMultimap.getValue(PREFIX_MEETING_TIME).isPresent()
                 ? Optional.of(ParserUtil.parseMeetingTime(argMultimap.getValue(PREFIX_MEETING_TIME).get()))
                 : Optional.empty();
         Set<Tag> tagList = ParserUtil.parseTags(argMultimap.getAllValues(PREFIX_TAG));
 
         // TODO: temporary fix, implement add Client and Lead commands
-        Lead lead = new Lead(name, phone, email, address, meetingTime, tagList);
+        Lead lead = new Lead(name, phone, email, address, keyMilestone, meetingTime, tagList);
 
         return new AddLeadCommand(lead);
     }
diff --git a/src/main/java/seedu/address/logic/parser/AddressBookParser.java b/src/main/java/seedu/address/logic/parser/AddressBookParser.java
index 8121dc888f3..f368d4c7d48 100644
--- a/src/main/java/seedu/address/logic/parser/AddressBookParser.java
+++ b/src/main/java/seedu/address/logic/parser/AddressBookParser.java
@@ -15,6 +15,7 @@
 import seedu.address.logic.commands.ConvertClientToLeadCommand;
 import seedu.address.logic.commands.ConvertLeadToClientCommand;
 import seedu.address.logic.commands.DeleteCommand;
+import seedu.address.logic.commands.DeleteMeetingCommand;
 import seedu.address.logic.commands.EditCommand;
 import seedu.address.logic.commands.ExitCommand;
 import seedu.address.logic.commands.FindCommand;
@@ -71,6 +72,9 @@ public Command parseCommand(String userInput) throws ParseException {
         case DeleteCommand.COMMAND_WORD:
             return new DeleteCommandParser().parse(arguments);
 
+        case DeleteMeetingCommand.COMMAND_WORD:
+            return new DeleteMeetingCommandParser().parse(arguments);
+
         case ClearCommand.COMMAND_WORD:
             return new ClearCommand();
 
diff --git a/src/main/java/seedu/address/logic/parser/CliSyntax.java b/src/main/java/seedu/address/logic/parser/CliSyntax.java
index ca26f7aab7e..35e43589e6d 100644
--- a/src/main/java/seedu/address/logic/parser/CliSyntax.java
+++ b/src/main/java/seedu/address/logic/parser/CliSyntax.java
@@ -12,6 +12,7 @@ public class CliSyntax {
     public static final Prefix PREFIX_ADDRESS = new Prefix("a/");
     public static final Prefix PREFIX_MEETING_TIME = new Prefix("m/");
     public static final Prefix PREFIX_TAG = new Prefix("t/");
+    public static final Prefix PREFIX_KEY_MILESTONE = new Prefix("k/");
 
     public static final Prefix PREFIX_NAME_TP = new Prefix("--name");
     public static final Prefix PREFIX_PHONE_TP = new Prefix("--phone");
@@ -19,4 +20,5 @@ public class CliSyntax {
     public static final Prefix PREFIX_ADDRESS_TP = new Prefix("--address");
     public static final Prefix PREFIX_MEETING_TIME_TP = new Prefix("--meeting-time");
     public static final Prefix PREFIX_TAG_TP = new Prefix("--tag");
+    public static final Prefix PREFIX_KEYMILESTONE_TP = new Prefix("--key");
 }
diff --git a/src/main/java/seedu/address/logic/parser/DeleteMeetingCommandParser.java b/src/main/java/seedu/address/logic/parser/DeleteMeetingCommandParser.java
new file mode 100644
index 00000000000..def3dedc869
--- /dev/null
+++ b/src/main/java/seedu/address/logic/parser/DeleteMeetingCommandParser.java
@@ -0,0 +1,29 @@
+package seedu.address.logic.parser;
+
+import static seedu.address.logic.Messages.MESSAGE_INVALID_COMMAND_FORMAT;
+
+import seedu.address.commons.core.index.Index;
+import seedu.address.logic.commands.DeleteMeetingCommand;
+import seedu.address.logic.parser.exceptions.ParseException;
+
+/**
+ * Parses input arguments and creates a new DeleteMeetingCommand object
+ */
+public class DeleteMeetingCommandParser implements Parser<DeleteMeetingCommand> {
+
+    /**
+     * Parses the given {@code String} of arguments in the context of the DeleteMeetingCommand
+     * and returns a DeleteMeetingCommand object for execution.
+     * @throws ParseException if the user input does not conform the expected format
+     */
+    @Override
+    public DeleteMeetingCommand parse(String args) throws ParseException {
+        try {
+            Index index = ParserUtil.parseIndex(args);
+            return new DeleteMeetingCommand(index);
+        } catch (ParseException pe) {
+            throw new ParseException(
+                    String.format(MESSAGE_INVALID_COMMAND_FORMAT, DeleteMeetingCommand.MESSAGE_USAGE), pe);
+        }
+    }
+}
diff --git a/src/main/java/seedu/address/logic/parser/EditCommandParser.java b/src/main/java/seedu/address/logic/parser/EditCommandParser.java
index 1306876233a..6b8fec9125f 100644
--- a/src/main/java/seedu/address/logic/parser/EditCommandParser.java
+++ b/src/main/java/seedu/address/logic/parser/EditCommandParser.java
@@ -4,6 +4,7 @@
 import static seedu.address.logic.Messages.MESSAGE_INVALID_COMMAND_FORMAT;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_ADDRESS;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_EMAIL;
+import static seedu.address.logic.parser.CliSyntax.PREFIX_KEY_MILESTONE;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_MEETING_TIME;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_NAME;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_PHONE;
@@ -16,7 +17,9 @@
 
 import seedu.address.commons.core.index.Index;
 import seedu.address.logic.commands.EditCommand;
+import seedu.address.logic.commands.EditCommand.EditLeadDescriptor;
 import seedu.address.logic.commands.EditCommand.EditPersonDescriptor;
+import seedu.address.logic.commands.EditLeadCommand;
 import seedu.address.logic.parser.exceptions.ParseException;
 import seedu.address.model.tag.Tag;
 
@@ -32,9 +35,10 @@ public class EditCommandParser implements Parser<EditCommand> {
      */
     public EditCommand parse(String args) throws ParseException {
         requireNonNull(args);
+        boolean isLead = false;
         ArgumentMultimap argMultimap =
-                ArgumentTokenizer.tokenize(args, PREFIX_NAME, PREFIX_PHONE, PREFIX_EMAIL,
-                        PREFIX_ADDRESS, PREFIX_MEETING_TIME, PREFIX_TAG);
+                ArgumentTokenizer.tokenize(args, PREFIX_NAME, PREFIX_PHONE, PREFIX_EMAIL, PREFIX_ADDRESS,
+                        PREFIX_KEY_MILESTONE, PREFIX_MEETING_TIME, PREFIX_TAG);
 
         Index index;
 
@@ -44,34 +48,49 @@ public EditCommand parse(String args) throws ParseException {
             throw new ParseException(String.format(MESSAGE_INVALID_COMMAND_FORMAT, EditCommand.MESSAGE_USAGE), pe);
         }
 
-        argMultimap.verifyNoDuplicatePrefixesFor(PREFIX_NAME, PREFIX_PHONE, PREFIX_EMAIL,
+        argMultimap.verifyNoDuplicatePrefixesFor(PREFIX_NAME, PREFIX_PHONE, PREFIX_EMAIL, PREFIX_KEY_MILESTONE,
                 PREFIX_MEETING_TIME, PREFIX_ADDRESS);
-
         EditPersonDescriptor editPersonDescriptor = new EditPersonDescriptor();
+        EditLeadDescriptor editLeadDescriptor = new EditLeadDescriptor();
+        if (argMultimap.getValue(PREFIX_KEY_MILESTONE).isPresent()) {
+            isLead = true;
+            editLeadDescriptor.setKeyMilestone(ParserUtil.parseKeyMilestone(
+                    argMultimap.getValue(PREFIX_KEY_MILESTONE).get()));
+        }
 
         if (argMultimap.getValue(PREFIX_NAME).isPresent()) {
             editPersonDescriptor.setName(ParserUtil.parseName(argMultimap.getValue(PREFIX_NAME).get()));
+            editLeadDescriptor.setName(ParserUtil.parseName(argMultimap.getValue(PREFIX_NAME).get()));
+
         }
         if (argMultimap.getValue(PREFIX_PHONE).isPresent()) {
             editPersonDescriptor.setPhone(ParserUtil.parsePhone(argMultimap.getValue(PREFIX_PHONE).get()));
+            editLeadDescriptor.setPhone(ParserUtil.parsePhone(argMultimap.getValue(PREFIX_PHONE).get()));
         }
         if (argMultimap.getValue(PREFIX_EMAIL).isPresent()) {
             editPersonDescriptor.setEmail(ParserUtil.parseEmail(argMultimap.getValue(PREFIX_EMAIL).get()));
+            editLeadDescriptor.setEmail(ParserUtil.parseEmail(argMultimap.getValue(PREFIX_EMAIL).get()));
         }
         if (argMultimap.getValue(PREFIX_ADDRESS).isPresent()) {
             editPersonDescriptor.setAddress(ParserUtil.parseAddress(argMultimap.getValue(PREFIX_ADDRESS).get()));
+            editLeadDescriptor.setAddress(ParserUtil.parseAddress(argMultimap.getValue(PREFIX_ADDRESS).get()));
         }
         if (argMultimap.getValue(PREFIX_MEETING_TIME).isPresent()) {
             editPersonDescriptor.setMeetingTime(
                     Optional.of(ParserUtil.parseMeetingTime(argMultimap.getValue(PREFIX_MEETING_TIME).get())));
         }
         parseTagsForEdit(argMultimap.getAllValues(PREFIX_TAG)).ifPresent(editPersonDescriptor::setTags);
+        parseTagsForEdit(argMultimap.getAllValues(PREFIX_TAG)).ifPresent(editLeadDescriptor::setTags);
 
-        if (!editPersonDescriptor.isAnyFieldEdited()) {
+        if (!isLead && !editPersonDescriptor.isAnyFieldEdited()) {
             throw new ParseException(EditCommand.MESSAGE_NOT_EDITED);
+        } else if (isLead && !editLeadDescriptor.isAnyFieldEdited()) {
+            throw new ParseException(EditLeadCommand.MESSAGE_NOT_EDITED);
         }
-
-        return new EditCommand(index, editPersonDescriptor);
+        //todo: there is a temporary fix here
+        //temporary fix to not convert lead to client when editing any lead's field
+        //EditLead is only used when the keyMilestone is changed
+        return isLead ? new EditLeadCommand(index, editLeadDescriptor) : new EditCommand(index, editPersonDescriptor);
     }
 
     /**
diff --git a/src/main/java/seedu/address/logic/parser/ParserUtil.java b/src/main/java/seedu/address/logic/parser/ParserUtil.java
index 6ee18e8a6b2..80d2db7d380 100644
--- a/src/main/java/seedu/address/logic/parser/ParserUtil.java
+++ b/src/main/java/seedu/address/logic/parser/ParserUtil.java
@@ -11,6 +11,7 @@
 import seedu.address.logic.parser.exceptions.ParseException;
 import seedu.address.model.person.Address;
 import seedu.address.model.person.Email;
+import seedu.address.model.person.KeyMilestone;
 import seedu.address.model.person.MeetingTime;
 import seedu.address.model.person.Name;
 import seedu.address.model.person.Phone;
@@ -81,6 +82,20 @@ public static Address parseAddress(String address) throws ParseException {
         return new Address(trimmedAddress);
     }
 
+    /**
+     * Parses a {@code String keyMilestone} into an {@code KeyMilestone}.
+     * Leading and trailing whitespaces will be trimmed.
+     *
+     * @throws ParseException if the given {@code keyMilestone} is invalid.
+     */
+    public static KeyMilestone parseKeyMilestone(String keyMilestone) throws ParseException {
+        requireNonNull(keyMilestone);
+        String trimmedKeyMilestone = keyMilestone.trim();
+        if (!KeyMilestone.isValidKeyMilestone(trimmedKeyMilestone)) {
+            throw new ParseException(KeyMilestone.MESSAGE_CONSTRAINTS);
+        }
+        return new KeyMilestone(keyMilestone);
+    }
     /**
      * Parses a {@code String email} into an {@code Email}.
      * Leading and trailing whitespaces will be trimmed.
diff --git a/src/main/java/seedu/address/model/person/KeyMilestone.java b/src/main/java/seedu/address/model/person/KeyMilestone.java
new file mode 100644
index 00000000000..2e688bdda2b
--- /dev/null
+++ b/src/main/java/seedu/address/model/person/KeyMilestone.java
@@ -0,0 +1,77 @@
+package seedu.address.model.person;
+
+import static java.util.Objects.requireNonNull;
+import static seedu.address.commons.util.AppUtil.checkArgument;
+
+import java.time.LocalDate;
+import java.time.format.DateTimeFormatter;
+import java.time.format.DateTimeParseException;
+import java.time.format.ResolverStyle;
+
+/**
+ * Represents a lead's key milestone in the address book.
+ * Guarantees: immutable; is valid as declared in {@link #isValidKeyMilestone(String)}
+ */
+public class KeyMilestone {
+    public static final String DATE_FORMAT = "dd/MM/uuuu";
+
+    // Replace uuuu in format to yyyy to not confuse users
+    public static final String MESSAGE_CONSTRAINTS =
+            "Key milestone is the date of Lead's milestone moment, should be in the format of "
+            + DATE_FORMAT.replace("u", "y");
+
+    public final String value;
+
+    /**
+     * Constructs an {@code KeyMilestone}.
+     *
+     * @param keyMilestone A valid date.
+     */
+    public KeyMilestone(String keyMilestone) {
+        requireNonNull(keyMilestone);
+        checkArgument(isValidKeyMilestone(keyMilestone), MESSAGE_CONSTRAINTS);
+        this.value = keyMilestone;
+    }
+
+    /**
+     * Returns if a given string is a valid date.
+     */
+    public static boolean isValidKeyMilestone(String test) {
+        try {
+            LocalDate.parse(test,
+                    DateTimeFormatter
+                            .ofPattern(DATE_FORMAT)
+                            .withResolverStyle(ResolverStyle.STRICT));
+            return true;
+        } catch (DateTimeParseException e) {
+            return false;
+        }
+    }
+
+    @Override
+    public String toString() {
+        return value;
+    }
+
+
+    @Override
+    public boolean equals(Object other) {
+        if (other == this) {
+            return true;
+        }
+
+        // instanceof handles nulls
+        if (!(other instanceof KeyMilestone)) {
+            return false;
+        }
+
+        KeyMilestone otherName = (KeyMilestone) other;
+        return value.equals(otherName.value);
+    }
+
+    @Override
+    public int hashCode() {
+        return value.hashCode();
+    }
+
+}
diff --git a/src/main/java/seedu/address/model/person/Lead.java b/src/main/java/seedu/address/model/person/Lead.java
index 7cac3b65b4d..4073dd4f4e8 100644
--- a/src/main/java/seedu/address/model/person/Lead.java
+++ b/src/main/java/seedu/address/model/person/Lead.java
@@ -3,6 +3,7 @@
 import java.util.Optional;
 import java.util.Set;
 
+import seedu.address.commons.util.ToStringBuilder;
 import seedu.address.model.tag.Tag;
 
 /**
@@ -10,13 +11,19 @@
  */
 public class Lead extends Person {
     public static final String TYPE_LEAD = "lead";
+    private final KeyMilestone keyMilestone;
 
     /**
      * Every field must be present and not null.
      */
     public Lead(Name name, Phone phone, Email email, Address address,
-                Optional<MeetingTime> meetingTime, Set<Tag> tags) {
+                KeyMilestone keyMilestone, Optional<MeetingTime> meetingTime, Set<Tag> tags) {
         super(name, phone, email, new Type(TYPE_LEAD), address, meetingTime, tags);
+        this.keyMilestone = keyMilestone;
+    }
+
+    public KeyMilestone getKeyMilestone() {
+        return this.keyMilestone;
     }
 
     @Override
@@ -28,4 +35,19 @@ public boolean isClient() {
     public boolean isLead() {
         return true;
     }
+
+    @Override
+    public String toString() {
+        //todo: fix the get
+        return new ToStringBuilder(this)
+                .add("name", super.getName())
+                .add("phone", super.getPhone())
+                .add("email", super.getEmail())
+                .add("type", super.getType())
+                .add("address", super.getAddress())
+                .add("key milestone", this.keyMilestone)
+                .add("meetingTime", super.getMeetingTime())
+                .add("tags", super.getTags())
+                .toString();
+    }
 }
diff --git a/src/main/java/seedu/address/model/person/MeetingTime.java b/src/main/java/seedu/address/model/person/MeetingTime.java
index 4968418d281..5857861d9c6 100644
--- a/src/main/java/seedu/address/model/person/MeetingTime.java
+++ b/src/main/java/seedu/address/model/person/MeetingTime.java
@@ -11,7 +11,9 @@
  */
 public class MeetingTime {
 
-    public static final String MESSAGE_CONSTRAINTS = "Meeting time should be in the format of " + DATE_TIME_FORMAT;
+    // Replace uuuu in format to yyyy to not confuse users
+    public static final String MESSAGE_CONSTRAINTS = "Meeting time should be in the format of "
+            + DATE_TIME_FORMAT.replace("u", "y");
 
     public final LocalDateTime value;
 
diff --git a/src/main/java/seedu/address/model/person/MeetingTimeFormatter.java b/src/main/java/seedu/address/model/person/MeetingTimeFormatter.java
index d297bff94c6..82c21d2fb53 100644
--- a/src/main/java/seedu/address/model/person/MeetingTimeFormatter.java
+++ b/src/main/java/seedu/address/model/person/MeetingTimeFormatter.java
@@ -3,15 +3,18 @@
 import java.time.LocalDateTime;
 import java.time.format.DateTimeFormatter;
 import java.time.format.DateTimeParseException;
+import java.time.format.ResolverStyle;
 
 /**
  * Helper class for handling meeting time formatting and parsing.
  */
 public class MeetingTimeFormatter {
 
-    public static final String DATE_TIME_FORMAT = "dd/MM/yyyy HH:mm";
+    public static final String DATE_TIME_FORMAT = "dd/MM/uuuu HH:mm";
     private static DateTimeFormatter getFormatter() {
-        return DateTimeFormatter.ofPattern(DATE_TIME_FORMAT);
+        return DateTimeFormatter
+                .ofPattern(DATE_TIME_FORMAT)
+                .withResolverStyle(ResolverStyle.STRICT);
     }
 
     public static LocalDateTime parse(String meetingTime) {
diff --git a/src/main/java/seedu/address/model/util/SampleDataUtil.java b/src/main/java/seedu/address/model/util/SampleDataUtil.java
index 64e22b2b0b1..539da85fb42 100644
--- a/src/main/java/seedu/address/model/util/SampleDataUtil.java
+++ b/src/main/java/seedu/address/model/util/SampleDataUtil.java
@@ -10,6 +10,7 @@
 import seedu.address.model.person.Address;
 import seedu.address.model.person.Client;
 import seedu.address.model.person.Email;
+import seedu.address.model.person.KeyMilestone;
 import seedu.address.model.person.Lead;
 import seedu.address.model.person.MeetingTime;
 import seedu.address.model.person.Name;
@@ -36,13 +37,16 @@ public static Person[] getSamplePersons() {
                 getTagSet("neighbours")),
             new Lead(new Name("David Li"), new Phone("91031282"), new Email("lidavid@example.com"),
                 new Address("Blk 436 Serangoon Gardens Street 26, #16-43"),
-                    Optional.of(new MeetingTime("10/10/2023 14:30")),
+                new KeyMilestone("01/12/2023"), Optional.of(new MeetingTime("10/10/2023 14:30")),
                 getTagSet("family")),
             new Lead(new Name("Irfan Ibrahim"), new Phone("92492021"), new Email("irfan@example.com"),
-                new Address("Blk 47 Tampines Street 20, #17-35"), Optional.of(new MeetingTime("10/10/2023 14:30")),
+                new Address("Blk 47 Tampines Street 20, #17-35"),
+                new KeyMilestone("01/12/2023"),
+                    Optional.of(new MeetingTime("10/10/2023 14:30")),
                 getTagSet("classmates")),
             new Lead(new Name("Roy Balakrishnan"), new Phone("92624417"), new Email("royb@example.com"),
-                new Address("Blk 45 Aljunied Street 85, #11-31"), Optional.of(new MeetingTime("10/10/2023 14:30")),
+                new Address("Blk 45 Aljunied Street 85, #11-31"),
+                new KeyMilestone("01/12/2023"), Optional.of(new MeetingTime("10/10/2023 14:30")),
                 getTagSet("colleagues"))
         };
     }
diff --git a/src/main/java/seedu/address/storage/JsonAdaptedPerson.java b/src/main/java/seedu/address/storage/JsonAdaptedPerson.java
index 6f7ba2f93ea..9aa028a2b38 100644
--- a/src/main/java/seedu/address/storage/JsonAdaptedPerson.java
+++ b/src/main/java/seedu/address/storage/JsonAdaptedPerson.java
@@ -17,6 +17,7 @@
 import seedu.address.model.person.Address;
 import seedu.address.model.person.Client;
 import seedu.address.model.person.Email;
+import seedu.address.model.person.KeyMilestone;
 import seedu.address.model.person.Lead;
 import seedu.address.model.person.MeetingTime;
 import seedu.address.model.person.Name;
@@ -29,7 +30,6 @@
  * Jackson-friendly version of {@link Person}.
  */
 class JsonAdaptedPerson {
-
     public static final String MISSING_FIELD_MESSAGE_FORMAT = "Person's %s field is missing!";
 
     private final String name;
@@ -37,22 +37,27 @@ class JsonAdaptedPerson {
     private final String email;
     private final String type;
     private final String address;
+    private String keyMilestone;
     private String meetingTime;
     private final List<JsonAdaptedTag> tags = new ArrayList<>();
 
     /**
      * Constructs a {@code JsonAdaptedPerson} with the given person details.
      */
+
     @JsonCreator
     public JsonAdaptedPerson(@JsonProperty("name") String name, @JsonProperty("phone") String phone,
                              @JsonProperty("email") String email, @JsonProperty("type") String type,
-                             @JsonProperty("address") String address, @JsonProperty("meetingTime") String meetingTime,
+                             @JsonProperty("address") String address,
+                             @JsonProperty("keyMilestone") String keyMilestone,
+                             @JsonProperty("meetingTime") String meetingTime,
                              @JsonProperty("tags") List<JsonAdaptedTag> tags) {
         this.name = name;
         this.phone = phone;
         this.email = email;
         this.type = type;
         this.address = address;
+        this.keyMilestone = keyMilestone;
         if (meetingTime != null) {
             this.meetingTime = meetingTime;
         }
@@ -70,6 +75,10 @@ public JsonAdaptedPerson(Person source) {
         email = source.getEmail().value;
         address = source.getAddress().value;
         type = source.getType().value;
+        if (type == TYPE_LEAD) {
+            Lead sourceLead = (Lead) source;
+            keyMilestone = sourceLead.getKeyMilestone().value;
+        }
         meetingTime = source.getMeetingTime().map(MeetingTime::toString).orElse(null);
         tags.addAll(source.getTags().stream()
                 .map(JsonAdaptedTag::new)
@@ -137,7 +146,12 @@ public Person toModelType() throws IllegalValueException {
         if (type.equals(TYPE_CLIENT)) {
             return new Client(modelName, modelPhone, modelEmail, modelAddress, modelMeetingTime, modelTags);
         } else if (type.equals(TYPE_LEAD)) {
-            return new Lead(modelName, modelPhone, modelEmail, modelAddress, modelMeetingTime, modelTags);
+            if (!KeyMilestone.isValidKeyMilestone(keyMilestone)) {
+                throw new IllegalValueException(KeyMilestone.MESSAGE_CONSTRAINTS);
+            }
+            final KeyMilestone modelKeyMilestone = new KeyMilestone(keyMilestone);
+            return new Lead(modelName, modelPhone, modelEmail, modelAddress, modelKeyMilestone,
+                    modelMeetingTime, modelTags);
         } else {
             throw new IllegalValueException(Type.MESSAGE_CONSTRAINTS);
         }
diff --git a/src/main/java/seedu/address/ui/ViewWindow.java b/src/main/java/seedu/address/ui/ViewWindow.java
index c169cd79e3a..b9e9cc8e174 100644
--- a/src/main/java/seedu/address/ui/ViewWindow.java
+++ b/src/main/java/seedu/address/ui/ViewWindow.java
@@ -5,10 +5,12 @@
 
 import javafx.fxml.FXML;
 import javafx.scene.control.Label;
+import javafx.scene.image.ImageView;
 import javafx.scene.layout.FlowPane;
 import javafx.scene.layout.HBox;
 import javafx.scene.layout.Region;
 import seedu.address.commons.core.LogsCenter;
+import seedu.address.model.person.Lead;
 import seedu.address.model.person.Person;
 
 /**
@@ -42,6 +44,16 @@ public class ViewWindow extends UiPart<Region> {
     private Label address;
     @FXML
     private Label email;
+
+    @FXML
+    private Label keyMilestone;
+
+    @FXML
+    private ImageView keyMilestoneIcon;
+
+    @FXML
+    private Label keyMilestoneTitle;
+
     @FXML
     private HBox meetingTimeBox;
 
@@ -59,7 +71,7 @@ public class ViewWindow extends UiPart<Region> {
     public ViewWindow(Person person, int displayedIndex) {
         super(FXML);
         this.person = person;
-        //id.setText(displayedIndex + ".");
+        //id.setText(displayedIndex + ".")
         name.setText(person.getName().fullName);
         phone.setText(person.getPhone().value);
         address.setText(person.getAddress().value);
@@ -69,6 +81,18 @@ public ViewWindow(Person person, int displayedIndex) {
         } else {
             meetingTime.setText("");
             meetingTimeBox.setVisible(false);
+        if (person.isLead()) {
+            Lead convertedPerson = (Lead) person;
+            keyMilestoneIcon.setVisible(true);
+            keyMilestone.setManaged(true);
+            keyMilestoneTitle.setManaged(true);
+            //the key milestone title is added here to make it disappear entirely
+            keyMilestone.setText(convertedPerson.getKeyMilestone().value);
+        } else {
+            //keyMilestone should be at the last line of the ui, if not the empty line will be obvious
+            keyMilestoneIcon.setVisible(false);
+            keyMilestone.setManaged(false);
+            keyMilestoneTitle.setManaged(false);
         }
         Label label = new Label(person.getType().value);
         if (person.isClient()) {
diff --git a/src/main/resources/images/milestone.png b/src/main/resources/images/milestone.png
new file mode 100644
index 00000000000..79bf6e2d726
Binary files /dev/null and b/src/main/resources/images/milestone.png differ
diff --git a/src/main/resources/view/ViewWindow.fxml b/src/main/resources/view/ViewWindow.fxml
index b32aaca8ea5..87509247ae5 100644
--- a/src/main/resources/view/ViewWindow.fxml
+++ b/src/main/resources/view/ViewWindow.fxml
@@ -94,6 +94,20 @@
                 </Label>
                 <Label fx:id="meetingTime" styleClass="cell_small_label" />
             </HBox>
+            <HBox spacing="5" alignment="CENTER_LEFT">
+                <ImageView fx:id="keyMilestoneIcon" fitHeight="16" fitWidth="16" visible="false">
+                    <image>
+                        <Image url="@/images/milestone.png" />
+                    </image>
+                </ImageView >
+                <Label fx:id="keyMilestoneTitle" styleClass="cell_small_label" managed="false">
+                    <text>Key Milestone:</text>
+                </Label>
+                <Label fx:id="keyMilestone" styleClass="cell_small_label" text="\$keyMilestone" managed="false"/>
+            </HBox>
+            <HBox spacing="5" alignment="CENTER_LEFT">
+                <Label fx:id="otherInfo" styleClass="cell_small_label" />
+            </HBox>
         </VBox>
     </GridPane>
     <stylesheets>
diff --git a/src/test/data/JsonSerializableAddressBookTest/duplicatePersonAddressBook.json b/src/test/data/JsonSerializableAddressBookTest/duplicatePersonAddressBook.json
index 52979b18cbd..9986ce2153e 100644
--- a/src/test/data/JsonSerializableAddressBookTest/duplicatePersonAddressBook.json
+++ b/src/test/data/JsonSerializableAddressBookTest/duplicatePersonAddressBook.json
@@ -5,6 +5,7 @@
     "email": "alice@example.com",
     "type": "lead",
     "address": "123, Jurong West Ave 6, #08-111",
+    "keyMilestone": "01/12/2023",
     "meetingTime" : "25/10/2023 11:21",
     "tags": [ "Client", "friends" ]
   }, {
@@ -13,6 +14,7 @@
     "email": "pauline@example.com",
     "type": "lead",
     "address": "4th street",
+    "keyMilestone": "01/12/2023",
     "meetingTime" : "25/10/2023 11:21",
     "tags": [ "Client" ]
   } ]
diff --git a/src/test/data/JsonSerializableAddressBookTest/invalidPersonAddressBook.json b/src/test/data/JsonSerializableAddressBookTest/invalidPersonAddressBook.json
index 6cee5ad29fe..c5525e28b1e 100644
--- a/src/test/data/JsonSerializableAddressBookTest/invalidPersonAddressBook.json
+++ b/src/test/data/JsonSerializableAddressBookTest/invalidPersonAddressBook.json
@@ -4,6 +4,7 @@
     "phone": "9482424",
     "type": "invalidtype",
     "email": "invalid@email!3e",
+    "keyMilestone": null,
     "address": "4th street",
     "meetingTime" : "2a5/10/2023 112:21"
   } ]
diff --git a/src/test/data/JsonSerializableAddressBookTest/typicalPersonsAddressBook.json b/src/test/data/JsonSerializableAddressBookTest/typicalPersonsAddressBook.json
index ad762ebdb8a..e0d0e1c343e 100644
--- a/src/test/data/JsonSerializableAddressBookTest/typicalPersonsAddressBook.json
+++ b/src/test/data/JsonSerializableAddressBookTest/typicalPersonsAddressBook.json
@@ -6,7 +6,8 @@
     "email" : "alice@example.com",
     "type": "client",
     "address" : "123, Jurong West Ave 6, #08-111",
-    "meetingTime" : null,
+    "keyMilestone": null,
+    "meetingTime" : "12/12/2023 12:00",
     "tags" : [ "friends" ]
   }, {
     "name" : "Benson Meier",
@@ -14,6 +15,7 @@
     "email" : "johnd@example.com",
     "type": "client",
     "address" : "311, Clementi Ave 2, #02-25",
+    "keyMilestone": null,
     "meetingTime" : "12/12/2020 12:00",
     "tags" : [ "owesMoney", "friends" ]
   }, {
@@ -21,6 +23,7 @@
     "phone" : "95352563",
     "email" : "heinz@example.com",
     "type": "client",
+    "keyMilestone": null,
     "address" : "wall street",
     "meetingTime" : null,
     "tags" : []
@@ -30,6 +33,7 @@
     "email" : "cornelia@example.com",
     "type": "client",
     "address" : "10th street",
+    "keyMilestone": null,
     "meetingTime" : null,
     "tags" : [ "friends" ]
   }, {
@@ -37,14 +41,16 @@
     "phone" : "9482224",
     "email" : "werner@example.com",
     "type": "lead",
+    "keyMilestone": "01/12/2023",
     "address" : "michegan ave",
-    "meetingTime" : null,
+    "meetingTime" : "12/12/2023 12:00",
     "tags" : []
   }, {
     "name" : "Fiona Kunz",
     "phone" : "9482427",
     "email" : "lydia@example.com",
     "type": "lead",
+    "keyMilestone": "01/12/2023",
     "address" : "little tokyo",
     "meetingTime" : null,
     "tags" : []
@@ -53,6 +59,7 @@
     "phone" : "9482442",
     "email" : "anna@example.com",
     "type": "lead",
+    "keyMilestone": "01/12/2023",
     "address" : "4th street",
     "meetingTime" : null,
     "tags" : []
diff --git a/src/test/java/seedu/address/logic/commands/AddCommandTest.java b/src/test/java/seedu/address/logic/commands/AddCommandTest.java
index 61e44ccd13f..754fff4b07d 100644
--- a/src/test/java/seedu/address/logic/commands/AddCommandTest.java
+++ b/src/test/java/seedu/address/logic/commands/AddCommandTest.java
@@ -5,7 +5,8 @@
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import static seedu.address.testutil.Assert.assertThrows;
-import static seedu.address.testutil.TypicalPersons.ALICE;
+import static seedu.address.testutil.TypicalClients.ALICE;
+import static seedu.address.testutil.TypicalLeads.BENSON;
 
 import java.nio.file.Path;
 import java.util.ArrayList;
@@ -106,14 +107,20 @@ public void equalsForClientandLeads() {
         // different person -> returns false
         assertFalse(addClientCommand.equals(addLeadCommand));
     }
-    //todo: test to string method for client and lead
     @Test
-    public void toStringMethod() {
+    public void clientToStringMethod() {
         AddCommand addCommand = new AddCommand(ALICE);
         String expected = AddCommand.class.getCanonicalName() + "{toAdd=" + ALICE + "}";
         assertEquals(expected, addCommand.toString());
     }
 
+    //put a lead here
+    @Test
+    public void leadToStringMethod() {
+        AddCommand addCommand = new AddCommand(BENSON);
+        String expected = AddCommand.class.getCanonicalName() + "{toAdd=" + BENSON + "}";
+        assertEquals(expected, addCommand.toString());
+    }
     /**
      * A default model stub that have all of the methods failing.
      */
diff --git a/src/test/java/seedu/address/logic/commands/CommandTestUtil.java b/src/test/java/seedu/address/logic/commands/CommandTestUtil.java
index 0419b50e941..b8dd3821c3c 100644
--- a/src/test/java/seedu/address/logic/commands/CommandTestUtil.java
+++ b/src/test/java/seedu/address/logic/commands/CommandTestUtil.java
@@ -4,6 +4,7 @@
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_ADDRESS;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_EMAIL;
+import static seedu.address.logic.parser.CliSyntax.PREFIX_KEY_MILESTONE;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_MEETING_TIME;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_NAME;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_PHONE;
@@ -38,6 +39,9 @@ public class CommandTestUtil {
     public static final String VALID_MEETING_TIME_AMY = "10/10/2024 10:00";
     public static final String VALID_MEETING_TIME_BOB = "16/12/2023 11:00";
     public static final String VALID_TAG_HUSBAND = "husband";
+
+    public static final String VALID_KEY_MILESTONE_AMY = "01/12/2023";
+    public static final String VALID_KEY_MILESTONE_BOB = "01/12/2023";
     public static final String VALID_TAG_FRIEND = "friend";
 
     public static final String NAME_DESC_AMY = " " + PREFIX_NAME + VALID_NAME_AMY;
@@ -48,6 +52,7 @@ public class CommandTestUtil {
     public static final String EMAIL_DESC_BOB = " " + PREFIX_EMAIL + VALID_EMAIL_BOB;
     public static final String ADDRESS_DESC_AMY = " " + PREFIX_ADDRESS + VALID_ADDRESS_AMY;
     public static final String ADDRESS_DESC_BOB = " " + PREFIX_ADDRESS + VALID_ADDRESS_BOB;
+    public static final String KEY_MILESTONE_DESC_BOB = " " + PREFIX_KEY_MILESTONE + VALID_KEY_MILESTONE_BOB;
     public static final String MEETING_TIME_DESC_AMY = " " + PREFIX_MEETING_TIME + VALID_MEETING_TIME_AMY;
     public static final String MEETING_TIME_DESC_BOB = " " + PREFIX_MEETING_TIME + VALID_MEETING_TIME_BOB;
     public static final String TAG_DESC_FRIEND = " " + PREFIX_TAG + VALID_TAG_FRIEND;
diff --git a/src/test/java/seedu/address/logic/commands/ConvertClientToLeadCommandTest.java b/src/test/java/seedu/address/logic/commands/ConvertClientToLeadCommandTest.java
index 4c025ff8c6b..846d37edc08 100644
--- a/src/test/java/seedu/address/logic/commands/ConvertClientToLeadCommandTest.java
+++ b/src/test/java/seedu/address/logic/commands/ConvertClientToLeadCommandTest.java
@@ -37,7 +37,7 @@ public void constructorNullPersonThrowsNullPointerException() {
     public void executeClientConvertToLeadSuccess() throws CommandException {
         final String expectedOutput = "Converted Client to Lead: Amy Bee; Phone: 85355255; Email: amy@gmail.com; "
                 + "Address: 123, Jurong West Ave 6, #08-111; "
-                + "Meeting Time: null; Tags: ";
+                + "Key Milestone: null; Meeting Time: null; Tags: ";
 
         // Step 1: Set up the necessary test data and model stub.
         ModelStubAcceptingClientAdded modelStub = new ModelStubAcceptingClientAdded();
diff --git a/src/test/java/seedu/address/logic/commands/DeleteMeetingCommandTest.java b/src/test/java/seedu/address/logic/commands/DeleteMeetingCommandTest.java
new file mode 100644
index 00000000000..913c5131a28
--- /dev/null
+++ b/src/test/java/seedu/address/logic/commands/DeleteMeetingCommandTest.java
@@ -0,0 +1,167 @@
+package seedu.address.logic.commands;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.junit.jupiter.api.Assertions.fail;
+import static seedu.address.logic.commands.CommandTestUtil.assertCommandSuccess;
+import static seedu.address.logic.commands.CommandTestUtil.showPersonAtIndex;
+import static seedu.address.testutil.TypicalIndexes.INDEX_FIRST_PERSON;
+import static seedu.address.testutil.TypicalIndexes.INDEX_SECOND_PERSON;
+import static seedu.address.testutil.TypicalPersons.getTypicalAddressBook;
+
+import org.junit.jupiter.api.Test;
+
+import seedu.address.commons.core.index.Index;
+import seedu.address.logic.Messages;
+import seedu.address.model.Model;
+import seedu.address.model.ModelManager;
+import seedu.address.model.UserPrefs;
+import seedu.address.model.person.Person;
+import seedu.address.testutil.PersonBuilder;
+
+/**
+ * Contains integration tests (interaction with the Model) and unit tests for
+ * {@code DeleteMeetingCommand}.
+ */
+public class DeleteMeetingCommandTest {
+
+    private Model model = new ModelManager(getTypicalAddressBook(), new UserPrefs());
+
+    @Test
+    public void execute_validIndexUnfilteredList_success() {
+        Person personToDeleteMeeting = model.getFilteredPersonList().get(INDEX_FIRST_PERSON.getZeroBased());
+        Person personWithMeetingDeleted = new PersonBuilder(personToDeleteMeeting)
+                .withMeetingTime(null).buildClient(); // First person in typical address book without meeting time
+
+        DeleteMeetingCommand deleteMeetingCommand = new DeleteMeetingCommand(INDEX_FIRST_PERSON);
+
+        String expectedMessage = String.format(DeleteMeetingCommand.MESSAGE_DELETE_MEETING_SUCCESS,
+                personToDeleteMeeting.getMeetingTimeString(), INDEX_FIRST_PERSON.getOneBased());
+
+        ModelManager expectedModel = new ModelManager(model.getAddressBook(), new UserPrefs());
+        expectedModel.setPerson(personToDeleteMeeting, personWithMeetingDeleted);
+
+        assertCommandSuccess(deleteMeetingCommand, model, expectedMessage, expectedModel);
+    }
+
+    @Test
+    public void execute_invalidIndexUnfilteredList_throwsCommandException() {
+        Index outOfBoundIndex = Index.fromOneBased(
+                model.getFilteredPersonList().size() + 1); // Last person in typical address book
+        DeleteMeetingCommand deleteMeetingCommand = new DeleteMeetingCommand(outOfBoundIndex);
+
+        CommandTestUtil.assertCommandFailure(deleteMeetingCommand, model,
+                Messages.MESSAGE_INVALID_PERSON_DISPLAYED_INDEX);
+    }
+
+    @Test
+    public void execute_validIndexFilteredList_success() {
+        showPersonAtIndex(model, INDEX_FIRST_PERSON);
+
+        Person personToDeleteMeeting = model.getFilteredPersonList().get(INDEX_FIRST_PERSON.getZeroBased());
+        Person personWithMeetingDeleted = new PersonBuilder(personToDeleteMeeting)
+                .withMeetingTime(null).buildClient(); // First person in typical address book without meeting time
+
+        DeleteMeetingCommand deleteMeetingCommand = new DeleteMeetingCommand(INDEX_FIRST_PERSON);
+
+        String expectedMessage = String.format(DeleteMeetingCommand.MESSAGE_DELETE_MEETING_SUCCESS,
+                personToDeleteMeeting.getMeetingTimeString(), INDEX_FIRST_PERSON.getOneBased());
+
+        Model expectedModel = new ModelManager(model.getAddressBook(), new UserPrefs());
+        expectedModel.setPerson(personToDeleteMeeting, personWithMeetingDeleted);
+
+        assertCommandSuccess(deleteMeetingCommand, model, expectedMessage, expectedModel);
+    }
+
+    @Test
+    public void execute_invalidIndexFilteredList_throwsCommandException() {
+        showPersonAtIndex(model, INDEX_FIRST_PERSON);
+
+        Index outOfBoundIndex = INDEX_SECOND_PERSON; // Second person in typical address book
+        // ensures that outOfBoundIndex is still in bounds of address book list
+        assertTrue(outOfBoundIndex.getZeroBased() < model.getAddressBook().getPersonList().size());
+
+        DeleteMeetingCommand deleteMeetingCommand = new DeleteMeetingCommand(outOfBoundIndex);
+
+        CommandTestUtil.assertCommandFailure(deleteMeetingCommand, model,
+                Messages.MESSAGE_INVALID_PERSON_DISPLAYED_INDEX);
+    }
+
+    @Test
+    public void deleteMeeting_personIsLead() {
+        Index indexFirstLead = Index.fromOneBased(5);
+        Person leadToDeleteMeeting = model.getFilteredPersonList().get(indexFirstLead.getZeroBased());
+        assertTrue(leadToDeleteMeeting.isLead());
+
+        Person leadWithMeetingDeleted = new PersonBuilder(leadToDeleteMeeting)
+                .withMeetingTime(null).buildLead(); // First lead in typical address book without meeting time
+
+        DeleteMeetingCommand deleteMeetingCommand = new DeleteMeetingCommand(indexFirstLead);
+
+        try {
+            deleteMeetingCommand.execute(model);
+        } catch (Exception e) {
+            fail();
+        }
+
+        Person expectedLead = model.getFilteredPersonList().get(indexFirstLead.getZeroBased());
+
+        assertTrue(expectedLead.isLead());
+        assertEquals(expectedLead, leadWithMeetingDeleted);
+    }
+
+    @Test
+    public void deleteMeeting_personNoMeetingTime_returnsPerson() {
+        Index indexPersonWithNoMeeting = Index.fromOneBased(3); // Third person in typical address book
+        Person personToDeleteMeeting = model.getFilteredPersonList()
+                .get(indexPersonWithNoMeeting.getZeroBased());
+
+        assertTrue(personToDeleteMeeting.getMeetingTime().isEmpty());
+
+        Person personWithMeetingDeleted = new PersonBuilder(personToDeleteMeeting)
+                .withMeetingTime(null).buildClient();
+        assertEquals(personToDeleteMeeting, personWithMeetingDeleted);
+
+        DeleteMeetingCommand deleteMeetingCommand = new DeleteMeetingCommand(indexPersonWithNoMeeting);
+
+        try {
+            deleteMeetingCommand.execute(model);
+        } catch (Exception e) {
+            fail();
+        }
+
+        Person expectedPerson = model.getFilteredPersonList().get(indexPersonWithNoMeeting.getZeroBased());
+        assertEquals(expectedPerson, personWithMeetingDeleted);
+    }
+
+    @Test
+    public void equals() {
+        DeleteMeetingCommand deleteMeetingFirstCommand = new DeleteMeetingCommand(INDEX_FIRST_PERSON);
+        DeleteMeetingCommand deleteMeetingSecondCommand = new DeleteMeetingCommand(INDEX_SECOND_PERSON);
+
+        // same object -> returns true
+        assertTrue(deleteMeetingFirstCommand.equals(deleteMeetingFirstCommand));
+
+        // same values -> returns true
+        DeleteMeetingCommand deleteMeetingFirstCommandCopy = new DeleteMeetingCommand(INDEX_FIRST_PERSON);
+        assertTrue(deleteMeetingFirstCommand.equals(deleteMeetingFirstCommandCopy));
+
+        // different types -> returns false
+        assertFalse(deleteMeetingFirstCommand.equals(1));
+
+        // null -> returns false
+        assertFalse(deleteMeetingFirstCommand.equals(null));
+
+        // different person -> returns false
+        assertFalse(deleteMeetingFirstCommand.equals(deleteMeetingSecondCommand));
+    }
+
+    @Test
+    public void toStringMethod() {
+        Index targetIndex = Index.fromOneBased(1);
+        DeleteMeetingCommand deleteMeetingCommand = new DeleteMeetingCommand(targetIndex);
+        String expectedString = DeleteMeetingCommand.class.getCanonicalName() + "{targetIndex=" + targetIndex + "}";
+        assertTrue(deleteMeetingCommand.toString().equals(expectedString));
+    }
+}
diff --git a/src/test/java/seedu/address/logic/commands/EditCommandTest.java b/src/test/java/seedu/address/logic/commands/EditCommandTest.java
index 3b6860107e6..299fc7a8d89 100644
--- a/src/test/java/seedu/address/logic/commands/EditCommandTest.java
+++ b/src/test/java/seedu/address/logic/commands/EditCommandTest.java
@@ -5,6 +5,7 @@
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import static seedu.address.logic.commands.CommandTestUtil.DESC_AMY;
 import static seedu.address.logic.commands.CommandTestUtil.DESC_BOB;
+import static seedu.address.logic.commands.CommandTestUtil.VALID_MEETING_TIME_AMY;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_NAME_BOB;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_PHONE_BOB;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_TAG_HUSBAND;
@@ -37,7 +38,7 @@ public class EditCommandTest {
 
     @Test
     public void execute_allFieldsSpecifiedUnfilteredList_success() {
-        Person editedPerson = new PersonBuilder().buildClient();
+        Person editedPerson = new PersonBuilder().withMeetingTime(VALID_MEETING_TIME_AMY).buildClient();
         EditPersonDescriptor descriptor = new EditPersonDescriptorBuilder(editedPerson).build();
         EditCommand editCommand = new EditCommand(INDEX_FIRST_PERSON, descriptor);
 
@@ -48,15 +49,15 @@ public void execute_allFieldsSpecifiedUnfilteredList_success() {
 
         assertCommandSuccess(editCommand, model, expectedMessage, expectedModel);
     }
-
     @Test
     public void execute_someFieldsSpecifiedUnfilteredList_success() {
         Index indexLastPerson = Index.fromOneBased(model.getFilteredPersonList().size());
         Person lastPerson = model.getFilteredPersonList().get(indexLastPerson.getZeroBased());
+        assert(lastPerson.isLead());
 
         PersonBuilder personInList = new PersonBuilder(lastPerson);
         Person editedPerson = personInList.withName(VALID_NAME_BOB).withPhone(VALID_PHONE_BOB)
-                .withTags(VALID_TAG_HUSBAND).buildLead();
+                .withTags(VALID_TAG_HUSBAND).withKeyMilestone("01/12/2023").buildLead();
 
         EditPersonDescriptor descriptor = new EditPersonDescriptorBuilder().withName(VALID_NAME_BOB)
                 .withPhone(VALID_PHONE_BOB).withTags(VALID_TAG_HUSBAND).build();
diff --git a/src/test/java/seedu/address/logic/commands/EditLeadCommandTest.java b/src/test/java/seedu/address/logic/commands/EditLeadCommandTest.java
new file mode 100644
index 00000000000..19911f73f63
--- /dev/null
+++ b/src/test/java/seedu/address/logic/commands/EditLeadCommandTest.java
@@ -0,0 +1,194 @@
+package seedu.address.logic.commands;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static seedu.address.logic.commands.CommandTestUtil.DESC_BOB;
+import static seedu.address.logic.commands.CommandTestUtil.VALID_ADDRESS_AMY;
+import static seedu.address.logic.commands.CommandTestUtil.VALID_EMAIL_AMY;
+import static seedu.address.logic.commands.CommandTestUtil.VALID_KEY_MILESTONE_BOB;
+import static seedu.address.logic.commands.CommandTestUtil.VALID_NAME_AMY;
+import static seedu.address.logic.commands.CommandTestUtil.VALID_NAME_BOB;
+import static seedu.address.logic.commands.CommandTestUtil.VALID_PHONE_AMY;
+import static seedu.address.logic.commands.CommandTestUtil.VALID_PHONE_BOB;
+import static seedu.address.logic.commands.CommandTestUtil.VALID_TAG_FRIEND;
+import static seedu.address.logic.commands.CommandTestUtil.VALID_TAG_HUSBAND;
+import static seedu.address.logic.commands.CommandTestUtil.assertCommandFailure;
+import static seedu.address.logic.commands.CommandTestUtil.assertCommandSuccess;
+import static seedu.address.logic.commands.CommandTestUtil.showPersonAtIndex;
+import static seedu.address.testutil.TypicalIndexes.INDEX_FIRST_PERSON;
+import static seedu.address.testutil.TypicalIndexes.INDEX_SECOND_PERSON;
+import static seedu.address.testutil.TypicalLeads.getTypicalLeadsAddressBook;
+
+import org.junit.jupiter.api.Test;
+
+import seedu.address.commons.core.index.Index;
+import seedu.address.logic.Messages;
+import seedu.address.logic.commands.EditCommand.EditLeadDescriptor;
+import seedu.address.model.AddressBook;
+import seedu.address.model.Model;
+import seedu.address.model.ModelManager;
+import seedu.address.model.UserPrefs;
+import seedu.address.model.person.Lead;
+import seedu.address.model.person.Person;
+import seedu.address.testutil.EditLeadDescriptorBuilder;
+import seedu.address.testutil.PersonBuilder;
+
+class EditLeadCommandTest {
+    private EditLeadDescriptor descLeadAmy = new EditLeadDescriptorBuilder().withName(VALID_NAME_AMY)
+                .withPhone(VALID_PHONE_AMY).withEmail(VALID_EMAIL_AMY).withAddress(VALID_ADDRESS_AMY)
+                .withTags(VALID_TAG_FRIEND).build();
+    private Model model = new ModelManager(getTypicalLeadsAddressBook(), new UserPrefs());
+    @Test
+    public void execute_allFieldsSpecifiedUnfilteredList_success() {
+        //cannot change the value of meeting time from valid to null
+        Lead editedLead = new PersonBuilder().withMeetingTime("24/10/2023 12:30").buildLead();
+        EditLeadDescriptor descriptor = new EditLeadDescriptorBuilder(editedLead).build();
+        EditLeadCommand editLeadCommand = new EditLeadCommand(INDEX_FIRST_PERSON, descriptor);
+
+        String expectedMessage = String.format(EditLeadCommand.MESSAGE_EDIT_LEAD_SUCCESS, Messages.format(editedLead));
+
+        Model expectedModel = new ModelManager(new AddressBook(model.getAddressBook()), new UserPrefs());
+        expectedModel.setPerson(model.getFilteredPersonList().get(0), editedLead);
+        assertCommandSuccess(editLeadCommand, model, expectedMessage, expectedModel);
+    }
+    @Test
+    public void execute_someFieldsSpecifiedUnfilteredList_success() {
+        Index indexLastPerson = Index.fromOneBased(model.getFilteredPersonList().size());
+        Lead lastPerson = (Lead) model.getFilteredPersonList().get(indexLastPerson.getZeroBased());
+        assert (lastPerson.isLead());
+
+        PersonBuilder personInList = new PersonBuilder(lastPerson);
+        Lead editedPerson = personInList.withName(VALID_NAME_BOB).withPhone(VALID_PHONE_BOB)
+                .withTags(VALID_TAG_HUSBAND).withKeyMilestone(VALID_KEY_MILESTONE_BOB).buildLead();
+
+        EditLeadDescriptor descriptor = new EditLeadDescriptorBuilder().withName(VALID_NAME_BOB)
+                .withPhone(VALID_PHONE_BOB).withTags(VALID_TAG_HUSBAND).withKeyMilestone(VALID_KEY_MILESTONE_BOB)
+                .build();
+
+        EditLeadCommand editCommand = new EditLeadCommand(indexLastPerson, descriptor);
+
+        String expectedMessage = String.format(EditCommand.MESSAGE_EDIT_LEAD_SUCCESS, Messages.format(editedPerson));
+
+        Model expectedModel = new ModelManager(new AddressBook(model.getAddressBook()), new UserPrefs());
+        expectedModel.setPerson(lastPerson, editedPerson);
+
+        assertCommandSuccess(editCommand, model, expectedMessage, expectedModel);
+    }
+
+    @Test
+    public void execute_noFieldSpecifiedUnfilteredList_success() {
+        EditLeadCommand editCommand = new EditLeadCommand(INDEX_FIRST_PERSON, new EditLeadDescriptor());
+        Lead editedPerson = (Lead) model.getFilteredPersonList().get(INDEX_FIRST_PERSON.getZeroBased());
+        assert (editedPerson.isLead());
+
+        String expectedMessage = String.format(EditCommand.MESSAGE_EDIT_LEAD_SUCCESS, Messages.format(editedPerson));
+
+        Model expectedModel = new ModelManager(new AddressBook(model.getAddressBook()), new UserPrefs());
+
+        assertCommandSuccess(editCommand, model, expectedMessage, expectedModel);
+    }
+
+    @Test
+    public void execute_filteredList_success() {
+        showPersonAtIndex(model, INDEX_FIRST_PERSON);
+
+        Lead personInFilteredList = (Lead) model.getFilteredPersonList().get(INDEX_FIRST_PERSON.getZeroBased());
+        assert(personInFilteredList.isLead());
+        Lead editedLead = new PersonBuilder(personInFilteredList).withName(VALID_NAME_BOB).buildLead();
+        EditLeadCommand editCommand = new EditLeadCommand(INDEX_FIRST_PERSON,
+                new EditLeadDescriptorBuilder().withName(VALID_NAME_BOB)
+                        .withKeyMilestone(VALID_KEY_MILESTONE_BOB).build());
+
+        String expectedMessage = String.format(EditCommand.MESSAGE_EDIT_LEAD_SUCCESS, Messages.format(editedLead));
+
+        Model expectedModel = new ModelManager(new AddressBook(model.getAddressBook()), new UserPrefs());
+        expectedModel.setPerson(model.getFilteredPersonList().get(0), editedLead);
+
+        assertCommandSuccess(editCommand, model, expectedMessage, expectedModel);
+    }
+
+    @Test
+    public void execute_duplicatePersonUnfilteredList_failure() {
+        Lead firstPerson = (Lead) model.getFilteredPersonList().get(INDEX_FIRST_PERSON.getZeroBased());
+        assert(firstPerson.isLead());
+        EditLeadDescriptor descriptor = new EditLeadDescriptorBuilder(firstPerson).build();
+        EditLeadCommand editCommand = new EditLeadCommand(INDEX_SECOND_PERSON, descriptor);
+
+        assertCommandFailure(editCommand, model, EditCommand.MESSAGE_DUPLICATE_PERSON);
+    }
+
+    @Test
+    public void execute_duplicatePersonFilteredList_failure() {
+        showPersonAtIndex(model, INDEX_FIRST_PERSON);
+
+        // edit person in filtered list into a duplicate in address book
+        Person personInList = model.getAddressBook().getPersonList().get(INDEX_SECOND_PERSON.getZeroBased());
+        assert(personInList.isLead());
+        EditLeadCommand editCommand = new EditLeadCommand(INDEX_FIRST_PERSON,
+                new EditLeadDescriptorBuilder((Lead) personInList).build());
+
+        assertCommandFailure(editCommand, model, EditCommand.MESSAGE_DUPLICATE_PERSON);
+    }
+
+    @Test
+    public void execute_invalidPersonIndexUnfilteredList_failure() {
+        Index outOfBoundIndex = Index.fromOneBased(model.getFilteredPersonList().size() + 1);
+        EditLeadDescriptor descriptor = new EditLeadDescriptorBuilder().withName(VALID_NAME_BOB).build();
+        EditLeadCommand editCommand = new EditLeadCommand(outOfBoundIndex, descriptor);
+
+        assertCommandFailure(editCommand, model, Messages.MESSAGE_INVALID_PERSON_DISPLAYED_INDEX);
+    }
+
+    /**
+     * Edit filtered list where index is larger than size of filtered list,
+     * but smaller than size of address book
+     */
+    @Test
+    public void execute_invalidPersonIndexFilteredList_failure() {
+        showPersonAtIndex(model, INDEX_FIRST_PERSON);
+        Index outOfBoundIndex = INDEX_SECOND_PERSON;
+        // ensures that outOfBoundIndex is still in bounds of address book list
+        assertTrue(outOfBoundIndex.getZeroBased() < model.getAddressBook().getPersonList().size());
+
+        EditLeadCommand editCommand = new EditLeadCommand(outOfBoundIndex,
+                new EditLeadDescriptorBuilder().withName(VALID_NAME_BOB).build());
+
+        assertCommandFailure(editCommand, model, Messages.MESSAGE_INVALID_PERSON_DISPLAYED_INDEX);
+    }
+
+    @Test
+    public void equals() {
+        final EditLeadCommand standardCommand = new EditLeadCommand(INDEX_FIRST_PERSON, descLeadAmy);
+
+        // same values -> returns true
+        EditLeadDescriptor copyDescriptor = new EditLeadDescriptor(descLeadAmy);
+        EditLeadCommand commandWithSameValues = new EditLeadCommand(INDEX_FIRST_PERSON, copyDescriptor);
+        assertTrue(standardCommand.equals(commandWithSameValues));
+
+        // same object -> returns true
+        assertTrue(standardCommand.equals(standardCommand));
+
+        // null -> returns false
+        assertFalse(standardCommand.equals(null));
+
+        // different types -> returns false
+        assertFalse(standardCommand.equals(new ClearCommand()));
+
+        // different index -> returns false
+        assertFalse(standardCommand.equals(new EditCommand(INDEX_SECOND_PERSON, descLeadAmy)));
+
+        // different descriptor -> returns false
+        assertFalse(standardCommand.equals(new EditCommand(INDEX_FIRST_PERSON, DESC_BOB)));
+    }
+
+    @Test
+    public void toStringMethod() {
+        Index index = Index.fromOneBased(1);
+        EditLeadDescriptor editLeadDescriptor = new EditLeadDescriptor();
+        EditLeadCommand editLeadCommand = new EditLeadCommand(index, editLeadDescriptor);
+        String expected = EditLeadCommand.class.getCanonicalName() + "{index=" + index + ", editLeadDescriptor="
+                + editLeadDescriptor + "}";
+        assertEquals(expected, editLeadCommand.toString());
+    }
+}
diff --git a/src/test/java/seedu/address/logic/parser/AddLeadCommandParserTest.java b/src/test/java/seedu/address/logic/parser/AddLeadCommandParserTest.java
index 1387db77826..b9973198a9d 100644
--- a/src/test/java/seedu/address/logic/parser/AddLeadCommandParserTest.java
+++ b/src/test/java/seedu/address/logic/parser/AddLeadCommandParserTest.java
@@ -10,6 +10,7 @@
 import static seedu.address.logic.commands.CommandTestUtil.INVALID_NAME_DESC;
 import static seedu.address.logic.commands.CommandTestUtil.INVALID_PHONE_DESC;
 import static seedu.address.logic.commands.CommandTestUtil.INVALID_TAG_DESC;
+import static seedu.address.logic.commands.CommandTestUtil.KEY_MILESTONE_DESC_BOB;
 import static seedu.address.logic.commands.CommandTestUtil.MEETING_TIME_DESC_AMY;
 import static seedu.address.logic.commands.CommandTestUtil.MEETING_TIME_DESC_BOB;
 import static seedu.address.logic.commands.CommandTestUtil.NAME_DESC_AMY;
@@ -22,12 +23,14 @@
 import static seedu.address.logic.commands.CommandTestUtil.TAG_DESC_HUSBAND;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_ADDRESS_BOB;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_EMAIL_BOB;
+import static seedu.address.logic.commands.CommandTestUtil.VALID_KEY_MILESTONE_BOB;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_NAME_BOB;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_PHONE_BOB;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_TAG_FRIEND;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_TAG_HUSBAND;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_ADDRESS;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_EMAIL;
+import static seedu.address.logic.parser.CliSyntax.PREFIX_KEY_MILESTONE;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_MEETING_TIME;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_NAME;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_PHONE;
@@ -53,11 +56,13 @@ public class AddLeadCommandParserTest {
 
     @Test
     public void parse_allFieldsPresent_success() {
-        Lead expectedLead = new PersonBuilder(BOB).withTags(VALID_TAG_FRIEND).buildLead();
+        Lead expectedLead = new PersonBuilder(BOB).withTags(VALID_TAG_FRIEND)
+                .withKeyMilestone(VALID_KEY_MILESTONE_BOB).buildLead();
 
         // whitespace only preamble
         assertParseSuccess(parser, PREAMBLE_WHITESPACE + NAME_DESC_BOB + PHONE_DESC_BOB + EMAIL_DESC_BOB
-                + ADDRESS_DESC_BOB + MEETING_TIME_DESC_BOB + TAG_DESC_FRIEND, new AddLeadCommand(expectedLead));
+                + ADDRESS_DESC_BOB + MEETING_TIME_DESC_BOB + TAG_DESC_FRIEND
+                + KEY_MILESTONE_DESC_BOB, new AddLeadCommand(expectedLead));
 
 
         // multiple tags - all accepted
@@ -65,14 +70,14 @@ public void parse_allFieldsPresent_success() {
                 .buildLead();
         assertParseSuccess(parser,
                 NAME_DESC_BOB + PHONE_DESC_BOB + EMAIL_DESC_BOB + ADDRESS_DESC_BOB
-                        + MEETING_TIME_DESC_BOB + TAG_DESC_HUSBAND + TAG_DESC_FRIEND,
+                        + MEETING_TIME_DESC_BOB + KEY_MILESTONE_DESC_BOB + TAG_DESC_HUSBAND + TAG_DESC_FRIEND,
                 new AddLeadCommand(expectedLeadMultipleTags));
     }
-
     @Test
-    public void parse_repeatedNonTagValue_failure() {
+    public void parseLead_repeatedNonTagValue_failure() {
+        //todo: need another test for clients in future
         String validExpectedPersonString = NAME_DESC_BOB + PHONE_DESC_BOB + EMAIL_DESC_BOB
-                + ADDRESS_DESC_BOB + MEETING_TIME_DESC_BOB + TAG_DESC_FRIEND;
+                + ADDRESS_DESC_BOB + KEY_MILESTONE_DESC_BOB + MEETING_TIME_DESC_BOB + TAG_DESC_FRIEND;
 
         // multiple names
         assertParseFailure(parser, NAME_DESC_AMY + validExpectedPersonString,
@@ -93,9 +98,9 @@ public void parse_repeatedNonTagValue_failure() {
         // multiple fields repeated
         assertParseFailure(parser,
                 validExpectedPersonString + PHONE_DESC_AMY + EMAIL_DESC_AMY
-                        + NAME_DESC_AMY + ADDRESS_DESC_AMY + MEETING_TIME_DESC_BOB
+                        + NAME_DESC_AMY + ADDRESS_DESC_AMY + KEY_MILESTONE_DESC_BOB + MEETING_TIME_DESC_BOB
                         + validExpectedPersonString,
-                Messages.getErrorMessageForDuplicatePrefixes(PREFIX_NAME, PREFIX_ADDRESS,
+                Messages.getErrorMessageForDuplicatePrefixes(PREFIX_NAME, PREFIX_ADDRESS, PREFIX_KEY_MILESTONE,
                         PREFIX_MEETING_TIME, PREFIX_EMAIL, PREFIX_PHONE));
 
         // invalid value followed by valid value
@@ -138,14 +143,16 @@ public void parse_repeatedNonTagValue_failure() {
     @Test
     public void parse_optionalFieldsMissing_success() {
         // zero tags
-        Lead expectedLead = new PersonBuilder(AMY).withTags().buildLead();
+        Lead expectedLead = new PersonBuilder(AMY).withTags().withKeyMilestone(VALID_KEY_MILESTONE_BOB).buildLead();
         assertParseSuccess(parser, NAME_DESC_AMY + PHONE_DESC_AMY + EMAIL_DESC_AMY
-                        + ADDRESS_DESC_AMY + MEETING_TIME_DESC_AMY, new AddLeadCommand(expectedLead));
+                        + ADDRESS_DESC_AMY + KEY_MILESTONE_DESC_BOB
+                + MEETING_TIME_DESC_AMY, new AddLeadCommand(expectedLead));
 
         // no meeting time
         Lead expectedLead2 = new PersonBuilder(BOB).withMeetingTime(null).buildLead();
         assertParseSuccess(parser, NAME_DESC_BOB + PHONE_DESC_BOB
-                        + EMAIL_DESC_BOB + ADDRESS_DESC_BOB + TAG_DESC_FRIEND + TAG_DESC_HUSBAND,
+                        + EMAIL_DESC_BOB + ADDRESS_DESC_BOB + KEY_MILESTONE_DESC_BOB
+                        + TAG_DESC_FRIEND + TAG_DESC_HUSBAND,
                 new AddLeadCommand(expectedLead2));
     }
 
@@ -177,32 +184,39 @@ public void parse_compulsoryFieldMissing_failure() {
     @Test
     public void parse_invalidValue_failure() {
         // invalid name
-        assertParseFailure(parser, INVALID_NAME_DESC + PHONE_DESC_BOB + EMAIL_DESC_BOB + ADDRESS_DESC_BOB
-                + MEETING_TIME_DESC_BOB + TAG_DESC_HUSBAND + TAG_DESC_FRIEND, Name.MESSAGE_CONSTRAINTS);
+        assertParseFailure(parser, INVALID_NAME_DESC + PHONE_DESC_BOB + EMAIL_DESC_BOB
+                + ADDRESS_DESC_BOB + KEY_MILESTONE_DESC_BOB + MEETING_TIME_DESC_BOB
+                + TAG_DESC_HUSBAND + TAG_DESC_FRIEND, Name.MESSAGE_CONSTRAINTS);
 
         // invalid phone
-        assertParseFailure(parser, NAME_DESC_BOB + INVALID_PHONE_DESC + EMAIL_DESC_BOB + ADDRESS_DESC_BOB
-                + MEETING_TIME_DESC_BOB + TAG_DESC_HUSBAND + TAG_DESC_FRIEND, Phone.MESSAGE_CONSTRAINTS);
+        assertParseFailure(parser, NAME_DESC_BOB + INVALID_PHONE_DESC + EMAIL_DESC_BOB
+                + ADDRESS_DESC_BOB + KEY_MILESTONE_DESC_BOB + MEETING_TIME_DESC_BOB
+                + TAG_DESC_HUSBAND + TAG_DESC_FRIEND, Phone.MESSAGE_CONSTRAINTS);
 
         // invalid email
-        assertParseFailure(parser, NAME_DESC_BOB + PHONE_DESC_BOB + INVALID_EMAIL_DESC + ADDRESS_DESC_BOB
-                + MEETING_TIME_DESC_BOB + TAG_DESC_HUSBAND + TAG_DESC_FRIEND, Email.MESSAGE_CONSTRAINTS);
+        assertParseFailure(parser, NAME_DESC_BOB + PHONE_DESC_BOB + INVALID_EMAIL_DESC
+                + ADDRESS_DESC_BOB + KEY_MILESTONE_DESC_BOB + MEETING_TIME_DESC_BOB
+                + TAG_DESC_HUSBAND + TAG_DESC_FRIEND, Email.MESSAGE_CONSTRAINTS);
 
         // invalid address
-        assertParseFailure(parser, NAME_DESC_BOB + PHONE_DESC_BOB + EMAIL_DESC_BOB + INVALID_ADDRESS_DESC
-                + MEETING_TIME_DESC_BOB + TAG_DESC_HUSBAND + TAG_DESC_FRIEND, Address.MESSAGE_CONSTRAINTS);
+        assertParseFailure(parser, NAME_DESC_BOB + PHONE_DESC_BOB + EMAIL_DESC_BOB
+                + INVALID_ADDRESS_DESC + KEY_MILESTONE_DESC_BOB + MEETING_TIME_DESC_BOB
+                + TAG_DESC_HUSBAND + TAG_DESC_FRIEND, Address.MESSAGE_CONSTRAINTS);
 
         // invalid tag
-        assertParseFailure(parser, NAME_DESC_BOB + PHONE_DESC_BOB + EMAIL_DESC_BOB + ADDRESS_DESC_BOB
-                + MEETING_TIME_DESC_BOB + INVALID_TAG_DESC + VALID_TAG_FRIEND, Tag.MESSAGE_CONSTRAINTS);
+        assertParseFailure(parser, NAME_DESC_BOB + PHONE_DESC_BOB + EMAIL_DESC_BOB
+                + ADDRESS_DESC_BOB + KEY_MILESTONE_DESC_BOB + MEETING_TIME_DESC_BOB
+                + INVALID_TAG_DESC + VALID_TAG_FRIEND, Tag.MESSAGE_CONSTRAINTS);
 
         // two invalid values, only first invalid value reported
-        assertParseFailure(parser, INVALID_NAME_DESC + PHONE_DESC_BOB + EMAIL_DESC_BOB + INVALID_ADDRESS_DESC
-                + MEETING_TIME_DESC_BOB, Name.MESSAGE_CONSTRAINTS);
+        assertParseFailure(parser, INVALID_NAME_DESC + PHONE_DESC_BOB + EMAIL_DESC_BOB
+                        + INVALID_ADDRESS_DESC + KEY_MILESTONE_DESC_BOB + MEETING_TIME_DESC_BOB,
+                Name.MESSAGE_CONSTRAINTS);
 
         // non-empty preamble
         assertParseFailure(parser, PREAMBLE_NON_EMPTY + NAME_DESC_BOB + PHONE_DESC_BOB + EMAIL_DESC_BOB
-                        + ADDRESS_DESC_BOB + MEETING_TIME_DESC_BOB + TAG_DESC_HUSBAND + TAG_DESC_FRIEND,
+                        + ADDRESS_DESC_BOB + KEY_MILESTONE_DESC_BOB + MEETING_TIME_DESC_BOB + TAG_DESC_HUSBAND
+                        + TAG_DESC_FRIEND,
                 String.format(MESSAGE_INVALID_COMMAND_FORMAT, AddLeadCommand.MESSAGE_USAGE));
     }
 }
diff --git a/src/test/java/seedu/address/logic/parser/AddressBookParserTest.java b/src/test/java/seedu/address/logic/parser/AddressBookParserTest.java
index c3b56840fdf..59771816997 100644
--- a/src/test/java/seedu/address/logic/parser/AddressBookParserTest.java
+++ b/src/test/java/seedu/address/logic/parser/AddressBookParserTest.java
@@ -20,8 +20,11 @@
 import seedu.address.logic.commands.AddLeadCommand;
 import seedu.address.logic.commands.ClearCommand;
 import seedu.address.logic.commands.DeleteCommand;
+import seedu.address.logic.commands.DeleteMeetingCommand;
 import seedu.address.logic.commands.EditCommand;
+import seedu.address.logic.commands.EditCommand.EditLeadDescriptor;
 import seedu.address.logic.commands.EditCommand.EditPersonDescriptor;
+import seedu.address.logic.commands.EditLeadCommand;
 import seedu.address.logic.commands.ExitCommand;
 import seedu.address.logic.commands.FindCommand;
 import seedu.address.logic.commands.HelpCommand;
@@ -34,11 +37,13 @@
 import seedu.address.model.person.Lead;
 import seedu.address.model.person.NameContainsKeywordsPredicate;
 import seedu.address.testutil.ClientUtil;
+import seedu.address.testutil.EditLeadDescriptorBuilder;
 import seedu.address.testutil.EditPersonDescriptorBuilder;
 import seedu.address.testutil.LeadUtil;
 import seedu.address.testutil.PersonBuilder;
 import seedu.address.testutil.PersonUtil;
 
+
 public class AddressBookParserTest {
 
     private final AddressBookParser parser = new AddressBookParser();
@@ -52,7 +57,7 @@ public void parseCommand_addClient() throws Exception {
 
     @Test
     public void parseCommand_addLead() throws Exception {
-        Lead lead = new PersonBuilder(ELLE).buildLead();
+        Lead lead = new PersonBuilder(ELLE).withKeyMilestone("01/12/2023").buildLead();
         AddLeadCommand command = (AddLeadCommand) parser.parseCommand(LeadUtil.getAddLeadCommand(lead));
         assertEquals(new AddLeadCommand(lead), command);
     }
@@ -69,6 +74,14 @@ public void parseCommand_delete() throws Exception {
                 DeleteCommand.COMMAND_WORD + " " + INDEX_FIRST_PERSON.getOneBased());
         assertEquals(new DeleteCommand(INDEX_FIRST_PERSON), command);
     }
+    //todo: test failed maybe because meeting time is null, should be fixed after merging master
+
+    @Test
+    public void parseCommand_deleteMeeting() throws Exception {
+        DeleteMeetingCommand command = (DeleteMeetingCommand) parser.parseCommand(
+                DeleteMeetingCommand.COMMAND_WORD + " " + INDEX_FIRST_PERSON.getOneBased());
+        assertEquals(new DeleteMeetingCommand(INDEX_FIRST_PERSON), command);
+    }
 
     @Test
     public void parseCommand_edit_withClient() throws Exception {
@@ -78,12 +91,11 @@ public void parseCommand_edit_withClient() throws Exception {
                 + INDEX_FIRST_PERSON.getOneBased() + " " + PersonUtil.getEditPersonDescriptorDetails(descriptor));
         assertEquals(new EditCommand(INDEX_FIRST_PERSON, descriptor), command);
     }
-
     @Test
     public void parseCommand_edit_withLead() throws Exception {
         Lead lead = new PersonBuilder().buildLead();
-        EditPersonDescriptor descriptor = new EditPersonDescriptorBuilder(lead).build();
-        EditCommand command = (EditCommand) parser.parseCommand(EditCommand.COMMAND_WORD + " "
+        EditLeadDescriptor descriptor = new EditLeadDescriptorBuilder(lead).build();
+        EditCommand command = (EditCommand) parser.parseCommand(EditLeadCommand.COMMAND_WORD + " "
                 + INDEX_FIRST_PERSON.getOneBased() + " " + PersonUtil.getEditPersonDescriptorDetails(descriptor));
         assertEquals(new EditCommand(INDEX_FIRST_PERSON, descriptor), command);
     }
diff --git a/src/test/java/seedu/address/logic/parser/DeleteMeetingCommandParserTest.java b/src/test/java/seedu/address/logic/parser/DeleteMeetingCommandParserTest.java
new file mode 100644
index 00000000000..59895eddb8b
--- /dev/null
+++ b/src/test/java/seedu/address/logic/parser/DeleteMeetingCommandParserTest.java
@@ -0,0 +1,32 @@
+package seedu.address.logic.parser;
+
+import static seedu.address.logic.Messages.MESSAGE_INVALID_COMMAND_FORMAT;
+import static seedu.address.logic.parser.CommandParserTestUtil.assertParseFailure;
+import static seedu.address.logic.parser.CommandParserTestUtil.assertParseSuccess;
+import static seedu.address.testutil.TypicalIndexes.INDEX_FIRST_PERSON;
+
+import org.junit.jupiter.api.Test;
+
+import seedu.address.logic.commands.DeleteMeetingCommand;
+
+public class DeleteMeetingCommandParserTest {
+
+    private DeleteMeetingCommandParser parser = new DeleteMeetingCommandParser();
+
+    @Test
+    public void parse_validArgs_returnsDeleteMeetingCommand() {
+        assertParseSuccess(parser, "1", new DeleteMeetingCommand(INDEX_FIRST_PERSON));
+    }
+
+    @Test
+    public void parse_invalidArgs_throwsParseException() {
+        assertParseFailure(parser, "a", String.format(MESSAGE_INVALID_COMMAND_FORMAT,
+                DeleteMeetingCommand.MESSAGE_USAGE));
+    }
+
+    @Test
+    public void parse_emptyArgs_throwsParseException() {
+        assertParseFailure(parser, "", String.format(MESSAGE_INVALID_COMMAND_FORMAT,
+                DeleteMeetingCommand.MESSAGE_USAGE));
+    }
+}
diff --git a/src/test/java/seedu/address/model/person/KeyMilestoneTest.java b/src/test/java/seedu/address/model/person/KeyMilestoneTest.java
new file mode 100644
index 00000000000..d1856703f6f
--- /dev/null
+++ b/src/test/java/seedu/address/model/person/KeyMilestoneTest.java
@@ -0,0 +1,49 @@
+package seedu.address.model.person;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import org.junit.jupiter.api.Test;
+
+class KeyMilestoneTest {
+
+    @Test
+    void isValidKeyMilestone() {
+        assertFalse(KeyMilestone.isValidKeyMilestone("01-01-2022"));
+        assertFalse(KeyMilestone.isValidKeyMilestone("01.01.2022"));
+        assertFalse(KeyMilestone.isValidKeyMilestone("2022-02-31"));
+        assertFalse(KeyMilestone.isValidKeyMilestone("2022-01-29"));
+        assertFalse(KeyMilestone.isValidKeyMilestone("2022-03-31"));
+        assertFalse(KeyMilestone.isValidKeyMilestone("31/02/2022"));
+
+        assertTrue(KeyMilestone.isValidKeyMilestone("01/01/2022"));
+        assertTrue(KeyMilestone.isValidKeyMilestone("31/03/2022"));
+    }
+
+    @Test
+    void equals() {
+        KeyMilestone keyMilestone = new KeyMilestone("01/12/2023");
+
+        // same values -> returns true
+        assertTrue(keyMilestone.equals(new KeyMilestone("01/12/2023")));
+
+        // same object -> returns true
+        assertTrue(keyMilestone.equals(keyMilestone));
+
+        // null -> returns false
+        assertFalse(keyMilestone.equals(null));
+
+        // different types -> returns false
+        assertFalse(keyMilestone.equals(5.0f));
+
+        // different values -> returns false
+        assertFalse(keyMilestone.equals(new KeyMilestone("01/01/2023")));
+    }
+
+    @Test
+    void hashCode_equals() {
+        assertEquals(new KeyMilestone("01/12/2023").hashCode(),
+                     new KeyMilestone("01/12/2023").hashCode());
+    }
+}
diff --git a/src/test/java/seedu/address/model/person/LeadTest.java b/src/test/java/seedu/address/model/person/LeadTest.java
index 83709bb31da..4b48f4d0a20 100644
--- a/src/test/java/seedu/address/model/person/LeadTest.java
+++ b/src/test/java/seedu/address/model/person/LeadTest.java
@@ -138,6 +138,7 @@ public void toStringMethod() {
                 + ", email=" + ALICE.getEmail()
                 + ", type=" + ALICE.getType()
                 + ", address=" + ALICE.getAddress()
+                + ", key milestone=" + ALICE.getKeyMilestone()
                 + ", meetingTime=" + ALICE.getMeetingTime()
                 + ", tags=" + ALICE.getTags() + "}";
         assertEquals(expected, ALICE.toString());
diff --git a/src/test/java/seedu/address/model/person/MeetingTimeTest.java b/src/test/java/seedu/address/model/person/MeetingTimeTest.java
index 7a074cbd457..0e4598ce4aa 100644
--- a/src/test/java/seedu/address/model/person/MeetingTimeTest.java
+++ b/src/test/java/seedu/address/model/person/MeetingTimeTest.java
@@ -1,5 +1,6 @@
 package seedu.address.model.person;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import static seedu.address.testutil.Assert.assertThrows;
@@ -58,4 +59,10 @@ public void equals() {
         // different values -> returns false
         assertFalse(meetingTime.equals(new MeetingTime("12/10/2025 10:20")));
     }
+
+    @Test
+    void hashCode_equals() {
+        assertEquals(new MeetingTime("12/10/2025 10:20").hashCode(),
+                new MeetingTime("12/10/2025 10:20").hashCode());
+    }
 }
diff --git a/src/test/java/seedu/address/storage/JsonAdaptedPersonTest.java b/src/test/java/seedu/address/storage/JsonAdaptedPersonTest.java
index 945ea347608..62f1138ad4c 100644
--- a/src/test/java/seedu/address/storage/JsonAdaptedPersonTest.java
+++ b/src/test/java/seedu/address/storage/JsonAdaptedPersonTest.java
@@ -18,7 +18,6 @@
 import seedu.address.model.person.MeetingTime;
 import seedu.address.model.person.Name;
 import seedu.address.model.person.Phone;
-
 public class JsonAdaptedPersonTest {
     private static final String INVALID_NAME = "R@chel";
     private static final String INVALID_PHONE = "+651234";
@@ -28,6 +27,9 @@ public class JsonAdaptedPersonTest {
     private static final String INVALID_MEETING_TIME = "1x/dd/2023 14:303";
     private static final String INVALID_TAG = "#friend";
 
+    private static final String VALID_KEYMILESTONE = "2022-12-01";
+    private static final String CLIENT_KEYMILESTONE_NULL = null;
+
     private static final String VALID_NAME = BENSON.getName().toString();
     private static final String VALID_PHONE = BENSON.getPhone().toString();
     private static final String VALID_EMAIL = BENSON.getEmail().toString();
@@ -37,7 +39,6 @@ public class JsonAdaptedPersonTest {
     private static final List<JsonAdaptedTag> VALID_TAGS = BENSON.getTags().stream()
             .map(JsonAdaptedTag::new)
             .collect(Collectors.toList());
-
     @Test
     public void toModelType_validPersonDetails_returnsPerson() throws Exception {
         JsonAdaptedPerson person = new JsonAdaptedPerson(BENSON);
@@ -48,23 +49,24 @@ public void toModelType_validPersonDetails_returnsPerson() throws Exception {
     public void toModelType_nullMeetingTimeWithOtherPersonDetailsValid_returnsPerson() throws Exception {
         JsonAdaptedPerson person =
                 new JsonAdaptedPerson(VALID_NAME, VALID_PHONE, VALID_EMAIL, VALID_TYPE,
-                        VALID_ADDRESS, null, VALID_TAGS);
+                        VALID_ADDRESS, null, null, VALID_TAGS);
         assertEquals(BENSON_NO_MEETING_TIME, person.toModelType());
     }
-
     @Test
     public void toModelType_invalidName_throwsIllegalValueException() {
         JsonAdaptedPerson person =
-                new JsonAdaptedPerson(INVALID_NAME, VALID_PHONE, VALID_EMAIL, VALID_TYPE,
-                        VALID_ADDRESS, VALID_MEETING_TIME, VALID_TAGS);
+                new JsonAdaptedPerson(INVALID_NAME, VALID_PHONE, VALID_EMAIL, VALID_TYPE, VALID_ADDRESS,
+                        CLIENT_KEYMILESTONE_NULL, VALID_MEETING_TIME, VALID_TAGS);
+
         String expectedMessage = Name.MESSAGE_CONSTRAINTS;
         assertThrows(IllegalValueException.class, expectedMessage, person::toModelType);
     }
 
     @Test
     public void toModelType_nullName_throwsIllegalValueException() {
-        JsonAdaptedPerson person = new JsonAdaptedPerson(null, VALID_PHONE, VALID_EMAIL, VALID_TYPE,
-                VALID_ADDRESS, VALID_MEETING_TIME, VALID_TAGS);
+        JsonAdaptedPerson person = new JsonAdaptedPerson(null, VALID_PHONE, VALID_EMAIL,
+                CLIENT_KEYMILESTONE_NULL, VALID_MEETING_TIME, VALID_TYPE, VALID_ADDRESS, VALID_TAGS);
+
         String expectedMessage = String.format(MISSING_FIELD_MESSAGE_FORMAT, Name.class.getSimpleName());
         assertThrows(IllegalValueException.class, expectedMessage, person::toModelType);
     }
@@ -72,25 +74,32 @@ public void toModelType_nullName_throwsIllegalValueException() {
     @Test
     public void toModelType_invalidPhone_throwsIllegalValueException() {
         JsonAdaptedPerson person =
-                new JsonAdaptedPerson(VALID_NAME, INVALID_PHONE, VALID_EMAIL, VALID_TYPE,
-                        VALID_ADDRESS, VALID_MEETING_TIME, VALID_TAGS);
+                new JsonAdaptedPerson(VALID_NAME, INVALID_PHONE, VALID_EMAIL, VALID_TYPE, VALID_ADDRESS,
+                        CLIENT_KEYMILESTONE_NULL, VALID_MEETING_TIME, VALID_TAGS);
         String expectedMessage = Phone.MESSAGE_CONSTRAINTS;
         assertThrows(IllegalValueException.class, expectedMessage, person::toModelType);
     }
 
     @Test
     public void toModelType_nullPhone_throwsIllegalValueException() {
+        JsonAdaptedPerson person = new JsonAdaptedPerson(VALID_NAME, null, VALID_EMAIL, CLIENT_KEYMILESTONE_NULL,
+                VALID_MEETING_TIME, VALID_TYPE, VALID_ADDRESS, VALID_TAGS);
+        String expectedMessage = String.format(MISSING_FIELD_MESSAGE_FORMAT, Phone.class.getSimpleName());
+        assertThrows(IllegalValueException.class, expectedMessage, person::toModelType);
+    }
+    //uncomment later
+    @Test
+    public void toModelType_nullPhoneWithValidKeyMilestone_throwsIllegalValueException() {
         JsonAdaptedPerson person = new JsonAdaptedPerson(VALID_NAME, null, VALID_EMAIL, VALID_TYPE,
-                VALID_ADDRESS, VALID_MEETING_TIME, VALID_TAGS);
+                VALID_ADDRESS, VALID_KEYMILESTONE, VALID_MEETING_TIME, VALID_TAGS);
         String expectedMessage = String.format(MISSING_FIELD_MESSAGE_FORMAT, Phone.class.getSimpleName());
         assertThrows(IllegalValueException.class, expectedMessage, person::toModelType);
     }
-
     @Test
     public void toModelType_invalidEmail_throwsIllegalValueException() {
         JsonAdaptedPerson person =
-                new JsonAdaptedPerson(VALID_NAME, VALID_PHONE, INVALID_EMAIL, VALID_TYPE,
-                        VALID_ADDRESS, VALID_MEETING_TIME, VALID_TAGS);
+                new JsonAdaptedPerson(VALID_NAME, VALID_PHONE, INVALID_EMAIL, VALID_TYPE, VALID_ADDRESS,
+                        CLIENT_KEYMILESTONE_NULL, VALID_MEETING_TIME, VALID_TAGS);
         String expectedMessage = Email.MESSAGE_CONSTRAINTS;
         assertThrows(IllegalValueException.class, expectedMessage, person::toModelType);
     }
@@ -98,7 +107,7 @@ public void toModelType_invalidEmail_throwsIllegalValueException() {
     @Test
     public void toModelType_nullEmail_throwsIllegalValueException() {
         JsonAdaptedPerson person = new JsonAdaptedPerson(VALID_NAME, VALID_PHONE, null, VALID_TYPE,
-                VALID_ADDRESS, VALID_MEETING_TIME, VALID_TAGS);
+                VALID_ADDRESS, CLIENT_KEYMILESTONE_NULL, VALID_MEETING_TIME, VALID_TAGS);
         String expectedMessage = String.format(MISSING_FIELD_MESSAGE_FORMAT, Email.class.getSimpleName());
         assertThrows(IllegalValueException.class, expectedMessage, person::toModelType);
     }
@@ -106,16 +115,16 @@ public void toModelType_nullEmail_throwsIllegalValueException() {
     @Test
     public void toModelType_invalidAddress_throwsIllegalValueException() {
         JsonAdaptedPerson person =
-                new JsonAdaptedPerson(VALID_NAME, VALID_PHONE, VALID_EMAIL, VALID_TYPE,
-                        INVALID_ADDRESS, VALID_MEETING_TIME, VALID_TAGS);
+                new JsonAdaptedPerson(VALID_NAME, VALID_PHONE, VALID_EMAIL, VALID_TYPE, INVALID_ADDRESS,
+                        CLIENT_KEYMILESTONE_NULL, VALID_MEETING_TIME, VALID_TAGS);
         String expectedMessage = Address.MESSAGE_CONSTRAINTS;
         assertThrows(IllegalValueException.class, expectedMessage, person::toModelType);
     }
 
     @Test
     public void toModelType_nullAddress_throwsIllegalValueException() {
-        JsonAdaptedPerson person = new JsonAdaptedPerson(VALID_NAME, VALID_PHONE, VALID_EMAIL, VALID_TYPE,
-                null, VALID_MEETING_TIME, VALID_TAGS);
+        JsonAdaptedPerson person = new JsonAdaptedPerson(VALID_NAME, VALID_PHONE, VALID_EMAIL, VALID_TYPE, null,
+                CLIENT_KEYMILESTONE_NULL, VALID_MEETING_TIME, VALID_TAGS);
         String expectedMessage = String.format(MISSING_FIELD_MESSAGE_FORMAT, Address.class.getSimpleName());
         assertThrows(IllegalValueException.class, expectedMessage, person::toModelType);
     }
@@ -123,16 +132,16 @@ public void toModelType_nullAddress_throwsIllegalValueException() {
     @Test
     public void toModelType_invalidType_throwsIllegalValueException() {
         JsonAdaptedPerson person =
-                new JsonAdaptedPerson(VALID_NAME, VALID_PHONE, VALID_EMAIL, INVALID_TYPE,
-                        VALID_ADDRESS, VALID_MEETING_TIME, VALID_TAGS);
+                new JsonAdaptedPerson(VALID_NAME, VALID_PHONE, VALID_EMAIL, INVALID_TYPE, VALID_ADDRESS,
+                        CLIENT_KEYMILESTONE_NULL, VALID_MEETING_TIME, VALID_TAGS);
         assertThrows(IllegalValueException.class, person::toModelType);
     }
 
     @Test
     public void toModelType_nullType_throwsIllegalValueException() {
         JsonAdaptedPerson person =
-                new JsonAdaptedPerson(VALID_NAME, VALID_PHONE, VALID_EMAIL, null,
-                        VALID_ADDRESS, VALID_MEETING_TIME, VALID_TAGS);
+                new JsonAdaptedPerson(VALID_NAME, VALID_PHONE, VALID_EMAIL, null, VALID_ADDRESS,
+                        CLIENT_KEYMILESTONE_NULL, VALID_MEETING_TIME, VALID_TAGS);
         assertThrows(IllegalValueException.class, person::toModelType);
     }
 
@@ -141,8 +150,25 @@ public void toModelType_invalidTags_throwsIllegalValueException() {
         List<JsonAdaptedTag> invalidTags = new ArrayList<>(VALID_TAGS);
         invalidTags.add(new JsonAdaptedTag(INVALID_TAG));
         JsonAdaptedPerson person =
-                new JsonAdaptedPerson(VALID_NAME, VALID_PHONE, VALID_EMAIL, VALID_TYPE,
-                        VALID_ADDRESS, VALID_MEETING_TIME, invalidTags);
+                new JsonAdaptedPerson(VALID_NAME, VALID_PHONE, VALID_EMAIL, VALID_TYPE, VALID_ADDRESS,
+                        CLIENT_KEYMILESTONE_NULL, VALID_MEETING_TIME, invalidTags);
+        assertThrows(IllegalValueException.class, person::toModelType);
+    }
+    @Test
+    public void toModelType_leadWithInvalidKeyMilestone_throwsIllegalValueException() {
+        String invalidKeyMilestone = "12345";
+        JsonAdaptedPerson person =
+                new JsonAdaptedPerson(VALID_NAME, VALID_PHONE, VALID_EMAIL, "lead", VALID_ADDRESS, "12345",
+                        VALID_MEETING_TIME, VALID_TAGS);
+        assertThrows(IllegalValueException.class, person::toModelType);
+    }
+    @Test
+    public void toModelType_invalidTagsWithValidKeyMilestone_throwsIllegalValueException() {
+        List<JsonAdaptedTag> invalidTags = new ArrayList<>(VALID_TAGS);
+        invalidTags.add(new JsonAdaptedTag(INVALID_TAG));
+        JsonAdaptedPerson person =
+                new JsonAdaptedPerson(VALID_NAME, VALID_PHONE, VALID_EMAIL, VALID_TYPE, VALID_ADDRESS,
+                        VALID_KEYMILESTONE, VALID_MEETING_TIME, invalidTags);
         assertThrows(IllegalValueException.class, person::toModelType);
     }
 
@@ -150,7 +176,7 @@ public void toModelType_invalidTags_throwsIllegalValueException() {
     public void toModelType_invalidMeetingTime_throwsIllegalValueException() {
         JsonAdaptedPerson person =
                 new JsonAdaptedPerson(VALID_NAME, VALID_PHONE, VALID_EMAIL, VALID_TYPE,
-                        VALID_ADDRESS, INVALID_MEETING_TIME, VALID_TAGS);
+                        VALID_ADDRESS, CLIENT_KEYMILESTONE_NULL, INVALID_MEETING_TIME, VALID_TAGS);
         String expectedMessage = MeetingTime.MESSAGE_CONSTRAINTS;
         assertThrows(IllegalValueException.class, expectedMessage, person::toModelType);
     }
diff --git a/src/test/java/seedu/address/testutil/EditLeadDescriptorBuilder.java b/src/test/java/seedu/address/testutil/EditLeadDescriptorBuilder.java
new file mode 100644
index 00000000000..c9ea44ed832
--- /dev/null
+++ b/src/test/java/seedu/address/testutil/EditLeadDescriptorBuilder.java
@@ -0,0 +1,115 @@
+package seedu.address.testutil;
+
+import java.util.Optional;
+import java.util.Set;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import seedu.address.logic.commands.EditCommand.EditLeadDescriptor;
+import seedu.address.model.person.Address;
+import seedu.address.model.person.Email;
+import seedu.address.model.person.KeyMilestone;
+import seedu.address.model.person.Lead;
+import seedu.address.model.person.MeetingTime;
+import seedu.address.model.person.Name;
+import seedu.address.model.person.Phone;
+import seedu.address.model.tag.Tag;
+
+/**
+ * A utility class to help with building EditLeadDescriptor objects.
+ *
+ */
+public class EditLeadDescriptorBuilder extends EditPersonDescriptorBuilder {
+    // not extending from EditPersonDescriptorBuilder as what we to change is leadDescriptor instance instead of
+    // personDescriptor
+
+    private EditLeadDescriptor leadDescriptor;
+
+    public EditLeadDescriptorBuilder() {
+        this.leadDescriptor = new EditLeadDescriptor();
+    }
+
+
+    public EditLeadDescriptorBuilder(EditLeadDescriptor descriptor) {
+        this.leadDescriptor = new EditLeadDescriptor(descriptor);
+    }
+
+    /**
+     * Returns an {@code EditLeadDescriptor} with fields containing {@code lead}'s details
+     */
+    public EditLeadDescriptorBuilder(Lead lead) {
+        leadDescriptor = new EditLeadDescriptor();
+        leadDescriptor.setName(lead.getName());
+        leadDescriptor.setPhone(lead.getPhone());
+        leadDescriptor.setEmail(lead.getEmail());
+        leadDescriptor.setAddress(lead.getAddress());
+        leadDescriptor.setKeyMilestone(lead.getKeyMilestone());
+        leadDescriptor.setMeetingTime(lead.getMeetingTime());
+        leadDescriptor.setTags(lead.getTags());
+    }
+
+
+    /**
+     * Sets the {@code Name} of the {@code EditLeadDescriptor} that we are building.
+     */
+    public EditLeadDescriptorBuilder withName(String name) {
+        leadDescriptor.setName(new Name(name));
+        return this;
+    }
+
+    /**
+     * Sets the {@code Phone} of the {@code EditLeadDescriptor} that we are building.
+     */
+    public EditLeadDescriptorBuilder withPhone(String phone) {
+        leadDescriptor.setPhone(new Phone(phone));
+        return this;
+    }
+
+    /**
+     * Sets the {@code Email} of the {@code EditLeadDescriptor} that we are building.
+     */
+    public EditLeadDescriptorBuilder withEmail(String email) {
+        leadDescriptor.setEmail(new Email(email));
+        return this;
+    }
+
+    /**
+     * Sets the {@code Address} of the {@code EditLeadDescriptor} that we are building.
+     */
+    public EditLeadDescriptorBuilder withAddress(String address) {
+        leadDescriptor.setAddress(new Address(address));
+        return this;
+    }
+
+    /**
+     * Sets the {@code KeyMilestone} of the {@code EditLeadDescriptor} that we are building.
+     */
+    public EditLeadDescriptorBuilder withKeyMilestone(String keyMilestone) {
+        leadDescriptor.setKeyMilestone(new KeyMilestone(keyMilestone));
+        return this;
+    }
+
+
+    /**
+     * Sets the {@code MeetingTime} of the {@code EditLeadDescriptor} that we are building.
+     */
+    public EditLeadDescriptorBuilder withMeetingTime(String meetingTime) {
+        leadDescriptor.setMeetingTime(Optional.of(new MeetingTime(meetingTime)));
+        return this;
+    }
+
+
+    /**
+     * Parses the {@code tags} into a {@code Set<Tag>} and set it to the {@code EditLeadDescriptor}
+     * that we are building.
+     */
+    public EditLeadDescriptorBuilder withTags(String... tags) {
+        Set<Tag> tagSet = Stream.of(tags).map(Tag::new).collect(Collectors.toSet());
+        leadDescriptor.setTags(tagSet);
+        return this;
+    }
+
+    public EditLeadDescriptor build() {
+        return leadDescriptor;
+    }
+}
diff --git a/src/test/java/seedu/address/testutil/EditPersonDescriptorBuilder.java b/src/test/java/seedu/address/testutil/EditPersonDescriptorBuilder.java
index 3bed347e88e..f7172efa197 100644
--- a/src/test/java/seedu/address/testutil/EditPersonDescriptorBuilder.java
+++ b/src/test/java/seedu/address/testutil/EditPersonDescriptorBuilder.java
@@ -29,6 +29,7 @@ public EditPersonDescriptorBuilder(EditPersonDescriptor descriptor) {
         this.descriptor = new EditPersonDescriptor(descriptor);
     }
 
+
     /**
      * Returns an {@code EditPersonDescriptor} with fields containing {@code person}'s details
      */
@@ -95,4 +96,5 @@ public EditPersonDescriptorBuilder withTags(String... tags) {
     public EditPersonDescriptor build() {
         return descriptor;
     }
+
 }
diff --git a/src/test/java/seedu/address/testutil/LeadUtil.java b/src/test/java/seedu/address/testutil/LeadUtil.java
index 44214b87598..8a44dacf9b1 100644
--- a/src/test/java/seedu/address/testutil/LeadUtil.java
+++ b/src/test/java/seedu/address/testutil/LeadUtil.java
@@ -2,6 +2,7 @@
 
 import static seedu.address.logic.parser.CliSyntax.PREFIX_ADDRESS;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_EMAIL;
+import static seedu.address.logic.parser.CliSyntax.PREFIX_KEY_MILESTONE;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_MEETING_TIME;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_NAME;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_PHONE;
@@ -25,12 +26,14 @@ public static String getAddLeadCommand(Lead lead) {
     /**
      * Returns the part of command string for the given {@code lead}'s details.
      */
-    private static String getLeadDetails(Lead lead) {
+    public static String getLeadDetails(Lead lead) {
         StringBuilder sb = new StringBuilder();
         sb.append(PREFIX_NAME + lead.getName().fullName + " ");
         sb.append(PREFIX_PHONE + lead.getPhone().value + " ");
         sb.append(PREFIX_EMAIL + lead.getEmail().value + " ");
         sb.append(PREFIX_ADDRESS + lead.getAddress().value + " ");
+        sb.append(PREFIX_KEY_MILESTONE + lead.getKeyMilestone().value + " ");
+
         lead.getMeetingTime().ifPresent(meetingTime -> sb.append(PREFIX_MEETING_TIME
                 + meetingTime.toString() + " "));
         lead.getTags().stream().forEach(
diff --git a/src/test/java/seedu/address/testutil/PersonBuilder.java b/src/test/java/seedu/address/testutil/PersonBuilder.java
index 57ed978572a..ddd34779e66 100644
--- a/src/test/java/seedu/address/testutil/PersonBuilder.java
+++ b/src/test/java/seedu/address/testutil/PersonBuilder.java
@@ -7,6 +7,7 @@
 import seedu.address.model.person.Address;
 import seedu.address.model.person.Client;
 import seedu.address.model.person.Email;
+import seedu.address.model.person.KeyMilestone;
 import seedu.address.model.person.Lead;
 import seedu.address.model.person.MeetingTime;
 import seedu.address.model.person.Name;
@@ -24,12 +25,15 @@ public class PersonBuilder {
     public static final String DEFAULT_PHONE = "85355255";
     public static final String DEFAULT_EMAIL = "amy@gmail.com";
     public static final String DEFAULT_ADDRESS = "123, Jurong West Ave 6, #08-111";
+    public static final String DEFAULT_KEY_MILESTONE = "01/12/2023";
+    public static final String DEFAULT_MEETING_TIME = "10/10/2023 14:30";
 
     private Name name;
     private Phone phone;
     private Email email;
     private Address address;
     private Set<Tag> tags;
+    private KeyMilestone keyMilestone;
     private Optional<MeetingTime> meetingTime;
 
     /**
@@ -41,6 +45,7 @@ public PersonBuilder() {
         email = new Email(DEFAULT_EMAIL);
         address = new Address(DEFAULT_ADDRESS);
         meetingTime = Optional.empty();
+        keyMilestone = new KeyMilestone(DEFAULT_KEY_MILESTONE);
         tags = new HashSet<>();
     }
 
@@ -56,6 +61,19 @@ public PersonBuilder(Person personToCopy) {
         tags = new HashSet<>(personToCopy.getTags());
     }
 
+    /**
+     * Initializes the PersonBuilder with the data of {@code leadToCopy}.
+     */
+    public PersonBuilder(Lead leadToCopy) {
+        name = leadToCopy.getName();
+        phone = leadToCopy.getPhone();
+        email = leadToCopy.getEmail();
+        address = leadToCopy.getAddress();
+        keyMilestone = leadToCopy.getKeyMilestone();
+        meetingTime = leadToCopy.getMeetingTime();
+        tags = new HashSet<>(leadToCopy.getTags());
+    }
+
     /**
      * Sets the {@code Name} of the {@code Person} that we are building.
      */
@@ -96,6 +114,14 @@ public PersonBuilder withEmail(String email) {
         return this;
     }
 
+    /**
+     * Sets the {@code KeyMilestone} of the {@code Person} that we are building.
+     */
+    //temporary fix: buildLead must call keyMilestone
+    public PersonBuilder withKeyMilestone(String keyMilestone) {
+        this.keyMilestone = new KeyMilestone(keyMilestone);
+        return this;
+    }
     /**
      * Sets the {@code MeetingTime} of the {@code Person} that we are building.
      */
@@ -113,6 +139,6 @@ public Client buildClient() {
     }
 
     public Lead buildLead() {
-        return new Lead(name, phone, email, address, meetingTime, tags);
+        return new Lead(name, phone, email, address, keyMilestone, meetingTime, tags);
     }
 }
diff --git a/src/test/java/seedu/address/testutil/TypicalClients.java b/src/test/java/seedu/address/testutil/TypicalClients.java
index c64c9ebcd76..4edf9b9eb0b 100644
--- a/src/test/java/seedu/address/testutil/TypicalClients.java
+++ b/src/test/java/seedu/address/testutil/TypicalClients.java
@@ -81,7 +81,6 @@ public static AddressBook getTypicalClientsAddressBook() {
     }
 
     public static List<Client> getTypicalClients() {
-        //todo: change here
         return new ArrayList<>(Arrays.asList(ALICE, BENSON, CARL, DANIEL, ELLE, FIONA, GEORGE));
     }
 }
diff --git a/src/test/java/seedu/address/testutil/TypicalLeads.java b/src/test/java/seedu/address/testutil/TypicalLeads.java
index 2f49e3b1d1e..2bc3f1f76bd 100644
--- a/src/test/java/seedu/address/testutil/TypicalLeads.java
+++ b/src/test/java/seedu/address/testutil/TypicalLeads.java
@@ -4,6 +4,8 @@
 import static seedu.address.logic.commands.CommandTestUtil.VALID_ADDRESS_BOB;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_EMAIL_AMY;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_EMAIL_BOB;
+import static seedu.address.logic.commands.CommandTestUtil.VALID_KEY_MILESTONE_AMY;
+import static seedu.address.logic.commands.CommandTestUtil.VALID_KEY_MILESTONE_BOB;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_MEETING_TIME_AMY;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_MEETING_TIME_BOB;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_NAME_AMY;
@@ -20,49 +22,82 @@
 import seedu.address.model.AddressBook;
 import seedu.address.model.person.Lead;
 
+
 /**
  * A utility class containing a list of {@code Lead} objects to be used in tests.
  */
 public class TypicalLeads {
     public static final Lead ALICE = new PersonBuilder().withName("Alice Pauline")
-            .withAddress("123, Jurong West Ave 6, #08-111").withEmail("alice@example.com")
+            .withAddress("123, Jurong West Ave 6, #08-111")
+            .withEmail("alice@example.com")
             .withPhone("94351253")
-            .withTags("friends").withMeetingTime("24/10/2023 12:30").buildLead();
+            .withKeyMilestone("01/12/2023")
+            .withMeetingTime("24/10/2023 12:30")
+            .withTags("friends")
+            .buildLead();
     public static final Lead BENSON = new PersonBuilder().withName("Benson Meier")
             .withAddress("311, Clementi Ave 2, #02-25")
             .withEmail("johnd@example.com").withPhone("98765432")
-            .withTags("owesMoney", "friends").withMeetingTime("24/10/2023 12:30").buildLead();
+            .withKeyMilestone("01/12/2023")
+            .withTags("owesMoney", "friends")
+            .withMeetingTime("24/10/2023 12:30")
+            .buildLead();
     public static final Lead CARL = new PersonBuilder().withName("Carl Kurz").withPhone("95352563")
-            .withEmail("heinz@example.com").withAddress("wall street")
-            .withMeetingTime("24/10/2023 12:30").buildLead();
+            .withEmail("heinz@example.com")
+            .withAddress("wall street")
+            .withKeyMilestone("01/12/2023")
+            .withMeetingTime("24/10/2023 12:30")
+            .buildLead();
     public static final Lead DANIEL = new PersonBuilder().withName("Daniel Meier").withPhone("87652533")
-            .withEmail("cornelia@example.com").withAddress("10th street").withTags("friends")
-            .withMeetingTime("24/10/2023 12:30").buildLead();
+            .withEmail("cornelia@example.com")
+            .withAddress("10th street")
+            .withTags("friends")
+            .withKeyMilestone("01/12/2023")
+            .withMeetingTime("24/10/2023 12:30")
+            .buildLead();
     public static final Lead ELLE = new PersonBuilder().withName("Elle Meyer").withPhone("9482224")
-            .withEmail("werner@example.com").withAddress("michegan ave")
-            .withMeetingTime("24/10/2023 12:30").buildLead();
+            .withEmail("werner@example.com")
+            .withAddress("michegan ave")
+            .withKeyMilestone("01/12/2023")
+            .withMeetingTime("24/10/2023 12:30")
+            .buildLead();
     public static final Lead FIONA = new PersonBuilder().withName("Fiona Kunz").withPhone("9482427")
-            .withEmail("lydia@example.com").withAddress("little tokyo")
-            .withMeetingTime("24/10/2023 12:30").buildLead();
+            .withEmail("lydia@example.com")
+            .withAddress("little tokyo")
+            .withKeyMilestone("01/12/2023")
+            .withMeetingTime("24/10/2023 12:30")
+            .buildLead();
     public static final Lead GEORGE = new PersonBuilder().withName("George Best").withPhone("9482442")
-            .withEmail("anna@example.com").withAddress("4th street")
-            .withMeetingTime("24/10/2023 12:30").buildLead();
+            .withEmail("anna@example.com")
+            .withAddress("4th street")
+            .withKeyMilestone("01/12/2023")
+            .withMeetingTime("24/10/2023 12:30")
+            .buildLead();
 
     // Manually added
     public static final Lead HOON = new PersonBuilder().withName("Hoon Meier").withPhone("8482424")
             .withEmail("stefan@example.com").withAddress("little india")
+            .withKeyMilestone("01/12/2023")
+            .withMeetingTime("24/10/2023 12:30")
             .withTags(VALID_TAG_FRIEND, VALID_TAG_HUSBAND).buildLead();
     public static final Lead IDA = new PersonBuilder().withName("Ida Mueller").withPhone("8482131")
-            .withEmail("hans@example.com").withAddress("chicago ave").withMeetingTime("24/10/2023 12:30").buildLead();
+            .withEmail("hans@example.com").withAddress("chicago ave")
+            .withKeyMilestone("01/12/2023")
+            .withMeetingTime("24/10/2023 12:30")
+            .buildLead();
 
     // Manually added - Lead's details found in {@code CommandTestUtil}
     public static final Lead AMY = new PersonBuilder().withName(VALID_NAME_AMY).withPhone(VALID_PHONE_AMY)
-            .withEmail(VALID_EMAIL_AMY).withAddress(VALID_ADDRESS_AMY)
-            .withTags(VALID_TAG_FRIEND).withMeetingTime(VALID_MEETING_TIME_AMY).buildLead();
+            .withEmail(VALID_EMAIL_AMY).withAddress(VALID_ADDRESS_AMY).withTags(VALID_TAG_FRIEND)
+            .withMeetingTime(VALID_MEETING_TIME_AMY)
+            .withKeyMilestone(VALID_KEY_MILESTONE_AMY).buildLead();
     public static final Lead BOB = new PersonBuilder().withName(VALID_NAME_BOB).withPhone(VALID_PHONE_BOB)
-            .withEmail(VALID_EMAIL_BOB).withAddress(VALID_ADDRESS_BOB)
+            .withEmail(VALID_EMAIL_BOB)
+            .withAddress(VALID_ADDRESS_BOB)
+            .withTags(VALID_TAG_HUSBAND, VALID_TAG_FRIEND)
+            .withKeyMilestone(VALID_KEY_MILESTONE_BOB)
             .withMeetingTime(VALID_MEETING_TIME_BOB)
-            .withTags(VALID_TAG_HUSBAND, VALID_TAG_FRIEND).buildLead();
+            .buildLead();
 
     public static final String KEYWORD_MATCHING_MEIER = "Meier"; // A keyword that matches MEIER
 
diff --git a/src/test/java/seedu/address/testutil/TypicalPersons.java b/src/test/java/seedu/address/testutil/TypicalPersons.java
index 566e333eada..90b791ffa4a 100644
--- a/src/test/java/seedu/address/testutil/TypicalPersons.java
+++ b/src/test/java/seedu/address/testutil/TypicalPersons.java
@@ -4,12 +4,15 @@
 import static seedu.address.logic.commands.CommandTestUtil.VALID_ADDRESS_BOB;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_EMAIL_AMY;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_EMAIL_BOB;
+import static seedu.address.logic.commands.CommandTestUtil.VALID_KEY_MILESTONE_BOB;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_MEETING_TIME_AMY;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_MEETING_TIME_BOB;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_NAME_AMY;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_NAME_BOB;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_PHONE_AMY;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_PHONE_BOB;
+import static seedu.address.logic.commands.CommandTestUtil.VALID_TAG_FRIEND;
+import static seedu.address.logic.commands.CommandTestUtil.VALID_TAG_HUSBAND;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -20,6 +23,7 @@
 import seedu.address.model.person.Lead;
 import seedu.address.model.person.Person;
 
+
 /**
  * A utility class containing a list of {@code Person} objects to be used in tests.
  */
@@ -27,7 +31,8 @@ public class TypicalPersons {
 
     public static final Client ALICE = new PersonBuilder().withName("Alice Pauline")
             .withAddress("123, Jurong West Ave 6, #08-111").withEmail("alice@example.com")
-            .withPhone("94351253").withTags("friends").buildClient();
+            .withPhone("94351253").withTags("friends")
+            .withMeetingTime("12/12/2023 12:00").buildClient();
     public static final Client BENSON = new PersonBuilder().withName("Benson Meier")
             .withAddress("311, Clementi Ave 2, #02-25")
             .withEmail("johnd@example.com").withPhone("98765432")
@@ -42,11 +47,12 @@ public class TypicalPersons {
     public static final Client DANIEL = new PersonBuilder().withName("Daniel Meier").withPhone("87652533")
             .withEmail("cornelia@example.com").withAddress("10th street").withTags("friends").buildClient();
     public static final Lead ELLE = new PersonBuilder().withName("Elle Meyer").withPhone("9482224")
-            .withEmail("werner@example.com").withAddress("michegan ave").buildLead();
+            .withEmail("werner@example.com").withAddress("michegan ave").withKeyMilestone("01/12/2023")
+            .withMeetingTime("12/12/2023 12:00").buildLead();
     public static final Lead FIONA = new PersonBuilder().withName("Fiona Kunz").withPhone("9482427")
-            .withEmail("lydia@example.com").withAddress("little tokyo").buildLead();
+            .withEmail("lydia@example.com").withAddress("little tokyo").withKeyMilestone("01/12/2023").buildLead();
     public static final Lead GEORGE = new PersonBuilder().withName("George Best").withPhone("9482442")
-            .withEmail("anna@example.com").withAddress("4th street").buildLead();
+            .withEmail("anna@example.com").withAddress("4th street").withKeyMilestone("01/12/2023").buildLead();
 
     // Manually added
     public static final Client HOON = new PersonBuilder().withName("Hoon Meier").withPhone("8482424")
@@ -59,8 +65,10 @@ public class TypicalPersons {
             .withEmail(VALID_EMAIL_AMY).withAddress(VALID_ADDRESS_AMY)
             .withMeetingTime(VALID_MEETING_TIME_AMY).buildClient();
     public static final Lead BOB = new PersonBuilder().withName(VALID_NAME_BOB).withPhone(VALID_PHONE_BOB)
-            .withEmail(VALID_EMAIL_BOB).withAddress(VALID_ADDRESS_BOB)
-            .withMeetingTime(VALID_MEETING_TIME_BOB).buildLead();
+            .withEmail(VALID_EMAIL_BOB).withAddress(VALID_ADDRESS_BOB).withTags(VALID_TAG_HUSBAND, VALID_TAG_FRIEND)
+            .withKeyMilestone(VALID_KEY_MILESTONE_BOB)
+            .withMeetingTime(VALID_MEETING_TIME_BOB)
+            .buildLead();
 
     public static final String KEYWORD_MATCHING_MEIER = "Meier"; // A keyword that matches MEIER