diff --git a/Sources/Amplitude/Amplitude.swift b/Sources/Amplitude/Amplitude.swift
index f14bd79b..e73b95f2 100644
--- a/Sources/Amplitude/Amplitude.swift
+++ b/Sources/Amplitude/Amplitude.swift
@@ -278,6 +278,13 @@ public class Amplitude {
         return sessions.sessionId
     }
 
+    @discardableResult
+    public func setSessionId(timestamp: Int64) -> Amplitude {
+        let sessionEvents = sessions.assignEventId(events: sessions.startNewSession(timestamp: timestamp))
+        sessionEvents.forEach { e in timeline.processEvent(event: e) }
+        return self
+    }
+
     @discardableResult
     public func reset() -> Amplitude {
         _ = setUserId(userId: nil)
diff --git a/Sources/Amplitude/ObjC/ObjCAmplitude.swift b/Sources/Amplitude/ObjC/ObjCAmplitude.swift
index eb47b46b..eea95c44 100644
--- a/Sources/Amplitude/ObjC/ObjCAmplitude.swift
+++ b/Sources/Amplitude/ObjC/ObjCAmplitude.swift
@@ -200,6 +200,13 @@ public class ObjCAmplitude: NSObject {
         amplitude.getSessionId()
     }
 
+    @objc(setSessionId:)
+    @discardableResult
+    public func setSessionId(timestamp: Int64) -> ObjCAmplitude {
+        amplitude.setSessionId(timestamp: timestamp)
+        return self
+    }
+
     @objc
     @discardableResult
     public func reset() -> ObjCAmplitude {
diff --git a/Sources/Amplitude/Sessions.swift b/Sources/Amplitude/Sessions.swift
index 424e684d..c8786a61 100644
--- a/Sources/Amplitude/Sessions.swift
+++ b/Sources/Amplitude/Sessions.swift
@@ -81,9 +81,13 @@ public class Sessions {
             result.append(event)
         }
 
+        return assignEventId(events: result)
+    }
+
+    func assignEventId(events: [BaseEvent]) -> [BaseEvent] {
         var newLastEventId = self.lastEventId
 
-        result.forEach({ event in
+        events.forEach({ event in
             if event.eventId == nil {
                 newLastEventId += 1
                 event.eventId = newLastEventId
@@ -92,7 +96,7 @@ public class Sessions {
 
         self.lastEventId = newLastEventId
 
-        return result
+        return events
     }
 
     private func isWithinMinTimeBetweenSessions(timestamp: Int64) -> Bool {
diff --git a/Tests/AmplitudeTests/AmplitudeSessionTests.swift b/Tests/AmplitudeTests/AmplitudeSessionTests.swift
index aa3d8eab..905af594 100644
--- a/Tests/AmplitudeTests/AmplitudeSessionTests.swift
+++ b/Tests/AmplitudeTests/AmplitudeSessionTests.swift
@@ -419,6 +419,103 @@ final class AmplitudeSessionTests: XCTestCase {
         XCTAssertEqual(event.eventId, lastEventId+4)
     }
 
+    func testSetSessionIdInBackgroundShouldStartNewSession() throws {
+        let lastEventId: Int64 = 123
+        try storageMem.write(key: StorageKey.LAST_EVENT_ID, value: lastEventId)
+
+        let amplitude = Amplitude(configuration: configuration)
+
+        let eventCollector = EventCollectorPlugin()
+        amplitude.add(plugin: eventCollector)
+
+        amplitude.track(event: BaseEvent(userId: "user", timestamp: 100, eventType: "test event 1"))
+        amplitude.setSessionId(timestamp: 150)
+        amplitude.track(event: BaseEvent(userId: "user", timestamp: 200, eventType: "test event 2"))
+
+        let collectedEvents = eventCollector.events
+
+        XCTAssertEqual(collectedEvents.count, 5)
+
+        var event = collectedEvents[0]
+        XCTAssertEqual(event.eventType, Constants.AMP_SESSION_START_EVENT)
+        XCTAssertEqual(event.sessionId, 100)
+        XCTAssertEqual(event.timestamp, 100)
+        XCTAssertEqual(event.eventId, lastEventId+1)
+
+        event = collectedEvents[1]
+        XCTAssertEqual(event.eventType, "test event 1")
+        XCTAssertEqual(event.sessionId, 100)
+        XCTAssertEqual(event.timestamp, 100)
+        XCTAssertEqual(event.eventId, lastEventId+2)
+
+        event = collectedEvents[2]
+        XCTAssertEqual(event.eventType, Constants.AMP_SESSION_END_EVENT)
+        XCTAssertEqual(event.sessionId, 100)
+        XCTAssertEqual(event.timestamp, 100)
+        XCTAssertEqual(event.eventId, lastEventId+3)
+
+        event = collectedEvents[3]
+        XCTAssertEqual(event.eventType, Constants.AMP_SESSION_START_EVENT)
+        XCTAssertEqual(event.sessionId, 150)
+        XCTAssertEqual(event.timestamp, 150)
+        XCTAssertEqual(event.eventId, lastEventId+4)
+
+        event = collectedEvents[4]
+        XCTAssertEqual(event.eventType, "test event 2")
+        XCTAssertEqual(event.sessionId, 150)
+        XCTAssertEqual(event.timestamp, 200)
+        XCTAssertEqual(event.eventId, lastEventId+5)
+    }
+
+    func testSetSessionIdInForegroundShouldStartNewSession() throws {
+        let lastEventId: Int64 = 123
+        try storageMem.write(key: StorageKey.LAST_EVENT_ID, value: lastEventId)
+
+        let amplitude = Amplitude(configuration: configuration)
+
+        let eventCollector = EventCollectorPlugin()
+        amplitude.add(plugin: eventCollector)
+
+        amplitude.onEnterForeground(timestamp: 1000)
+        amplitude.track(event: BaseEvent(userId: "user", timestamp: 1050, eventType: "test event 1"))
+        amplitude.setSessionId(timestamp: 1100)
+        amplitude.track(event: BaseEvent(userId: "user", timestamp: 2000, eventType: "test event 2"))
+
+        let collectedEvents = eventCollector.events
+
+        XCTAssertEqual(collectedEvents.count, 5)
+
+        var event = collectedEvents[0]
+        XCTAssertEqual(event.eventType, Constants.AMP_SESSION_START_EVENT)
+        XCTAssertEqual(event.sessionId, 1000)
+        XCTAssertEqual(event.timestamp, 1000)
+        XCTAssertEqual(event.eventId, lastEventId+1)
+
+        event = collectedEvents[1]
+        XCTAssertEqual(event.eventType, "test event 1")
+        XCTAssertEqual(event.sessionId, 1000)
+        XCTAssertEqual(event.timestamp, 1050)
+        XCTAssertEqual(event.eventId, lastEventId+2)
+
+        event = collectedEvents[2]
+        XCTAssertEqual(event.eventType, Constants.AMP_SESSION_END_EVENT)
+        XCTAssertEqual(event.sessionId, 1000)
+        XCTAssertEqual(event.timestamp, 1050)
+        XCTAssertEqual(event.eventId, lastEventId+3)
+
+        event = collectedEvents[3]
+        XCTAssertEqual(event.eventType, Constants.AMP_SESSION_START_EVENT)
+        XCTAssertEqual(event.sessionId, 1100)
+        XCTAssertEqual(event.timestamp, 1100)
+        XCTAssertEqual(event.eventId, lastEventId+4)
+
+        event = collectedEvents[4]
+        XCTAssertEqual(event.eventType, "test event 2")
+        XCTAssertEqual(event.sessionId, 1100)
+        XCTAssertEqual(event.timestamp, 2000)
+        XCTAssertEqual(event.eventId, lastEventId+5)
+    }
+
     func getDictionary(_ props: [String: Any?]) -> NSDictionary {
         return NSDictionary(dictionary: props as [AnyHashable: Any])
     }