How to add calendar events in Android?

Try this in your code:

Calendar cal = Calendar.getInstance();              
Intent intent = new Intent(Intent.ACTION_EDIT);
intent.setType("vnd.android.cursor.item/event");
intent.putExtra("beginTime", cal.getTimeInMillis());
intent.putExtra("allDay", true);
intent.putExtra("rrule", "FREQ=YEARLY");
intent.putExtra("endTime", cal.getTimeInMillis()+60*60*1000);
intent.putExtra("title", "A Test Event from android app");
startActivity(intent);

Use this API in your code.. It will help u to insert event, event with reminder and event with meeting can be enabled... This api works for platform 2.1 and above Those who uses less then 2.1 instead of content://com.android.calendar/events use content://calendar/events

 public static long pushAppointmentsToCalender(Activity curActivity, String title, String addInfo, String place, int status, long startDate, boolean needReminder, boolean needMailService) {
    /***************** Event: note(without alert) *******************/

    String eventUriString = "content://com.android.calendar/events";
    ContentValues eventValues = new ContentValues();

    eventValues.put("calendar_id", 1); // id, We need to choose from
                                        // our mobile for primary
                                        // its 1
    eventValues.put("title", title);
    eventValues.put("description", addInfo);
    eventValues.put("eventLocation", place);

    long endDate = startDate + 1000 * 60 * 60; // For next 1hr

    eventValues.put("dtstart", startDate);
    eventValues.put("dtend", endDate);

    // values.put("allDay", 1); //If it is bithday alarm or such
    // kind (which should remind me for whole day) 0 for false, 1
    // for true
    eventValues.put("eventStatus", status); // This information is
    // sufficient for most
    // entries tentative (0),
    // confirmed (1) or canceled
    // (2):
    eventValues.put("eventTimezone", "UTC/GMT +2:00");
   /*Comment below visibility and transparency  column to avoid java.lang.IllegalArgumentException column visibility is invalid error */

    /*eventValues.put("visibility", 3); // visibility to default (0),
                                        // confidential (1), private
                                        // (2), or public (3):
    eventValues.put("transparency", 0); // You can control whether
                                        // an event consumes time
                                        // opaque (0) or transparent
                                        // (1).
      */
    eventValues.put("hasAlarm", 1); // 0 for false, 1 for true

    Uri eventUri = curActivity.getApplicationContext().getContentResolver().insert(Uri.parse(eventUriString), eventValues);
    long eventID = Long.parseLong(eventUri.getLastPathSegment());

    if (needReminder) {
        /***************** Event: Reminder(with alert) Adding reminder to event *******************/

        String reminderUriString = "content://com.android.calendar/reminders";

        ContentValues reminderValues = new ContentValues();

        reminderValues.put("event_id", eventID);
        reminderValues.put("minutes", 5); // Default value of the
                                            // system. Minutes is a
                                            // integer
        reminderValues.put("method", 1); // Alert Methods: Default(0),
                                            // Alert(1), Email(2),
                                            // SMS(3)

        Uri reminderUri = curActivity.getApplicationContext().getContentResolver().insert(Uri.parse(reminderUriString), reminderValues);
    }

    /***************** Event: Meeting(without alert) Adding Attendies to the meeting *******************/

    if (needMailService) {
        String attendeuesesUriString = "content://com.android.calendar/attendees";

        /********
         * To add multiple attendees need to insert ContentValues multiple
         * times
         ***********/
        ContentValues attendeesValues = new ContentValues();

        attendeesValues.put("event_id", eventID);
        attendeesValues.put("attendeeName", "xxxxx"); // Attendees name
        attendeesValues.put("attendeeEmail", "[email protected]");// Attendee
                                                                            // E
                                                                            // mail
                                                                            // id
        attendeesValues.put("attendeeRelationship", 0); // Relationship_Attendee(1),
                                                        // Relationship_None(0),
                                                        // Organizer(2),
                                                        // Performer(3),
                                                        // Speaker(4)
        attendeesValues.put("attendeeType", 0); // None(0), Optional(1),
                                                // Required(2), Resource(3)
        attendeesValues.put("attendeeStatus", 0); // NOne(0), Accepted(1),
                                                    // Decline(2),
                                                    // Invited(3),
                                                    // Tentative(4)

        Uri attendeuesesUri = curActivity.getApplicationContext().getContentResolver().insert(Uri.parse(attendeuesesUriString), attendeesValues);
    }

    return eventID;

}

i used the code below, it solves my problem to add event in default device calendar in ICS and also on version less that ICS

    if (Build.VERSION.SDK_INT >= 14) {
        Intent intent = new Intent(Intent.ACTION_INSERT)
        .setData(Events.CONTENT_URI)
        .putExtra(CalendarContract.EXTRA_EVENT_BEGIN_TIME, beginTime.getTimeInMillis())
        .putExtra(CalendarContract.EXTRA_EVENT_END_TIME, endTime.getTimeInMillis())
        .putExtra(Events.TITLE, "Yoga")
        .putExtra(Events.DESCRIPTION, "Group class")
        .putExtra(Events.EVENT_LOCATION, "The gym")
        .putExtra(Events.AVAILABILITY, Events.AVAILABILITY_BUSY)
        .putExtra(Intent.EXTRA_EMAIL, "[email protected],[email protected]");
         startActivity(intent);
}

    else {
        Calendar cal = Calendar.getInstance();              
        Intent intent = new Intent(Intent.ACTION_EDIT);
        intent.setType("vnd.android.cursor.item/event");
        intent.putExtra("beginTime", cal.getTimeInMillis());
        intent.putExtra("allDay", true);
        intent.putExtra("rrule", "FREQ=YEARLY");
        intent.putExtra("endTime", cal.getTimeInMillis()+60*60*1000);
        intent.putExtra("title", "A Test Event from android app");
        startActivity(intent);
        }

Hope it would help.....

As of Android version 4.0 official APIs and intents are available to interact with the available calendar providers.