added readme. added dockblock to function

README.md

@@ -1,3 +1,22 @@
+This is a pre-release please do not use in production.
+
 # FieldtypeRecurringDates
 
-To do. 
+Fieldtype for definining recurring dates according to [RFC-RFC 5545)](https://www.rfc-editor.org/rfc/rfc5545#section-3.3.10) and the awesome library
+[php-rrule](https://github.com/rlanvin/php-rrule)
+
+# Finding occurrences
+
+You can use the module included in this same package to find the rules occurrences:
+
+```
+$output = $calendarRenderer->render(
+    $selector, [
+        'fields' => [
+            // Will find event occurrences in fields specified in this array 
+            'recurring_meetings',
+            'recurring_events'
+        ]
+    ]
+```
+

RecurringDatesFinder/RecurringDatesFinder.module

@@ -77,7 +77,16 @@ class RecurringDatesFinder extends WireData implements Module
 
         return $field_queries;
     }
-
+
+    /**
+     * @param $start string|int
+     * @param $end string|int
+     * @param $selector string
+     * @param $options array
+     *  - `fields` (string) : Selector.
+     * @return array|false
+     * @throws WireException
+     */
     public function find($start, $end, $selector = null, $options = array())
     {
         $field_queries = $this->getRecurringFieldQueries($start, $end, $selector, $options);