Events.Item.CalendarItemExternalIdentifier
------------------------------------------

A server-provided identifier for this calendar item.

| Component | Version | macOS | Windows | Linux | Server | iOS SDK |
|---|---|---|---|---|---|---|
| [Events](component_Events.md) | [6.2](newinversion62.md) | ✅ Yes | ❌ No | ❌ No | ❌ No | ✅ Yes |

MBS( "Events.Item.CalendarItemExternalIdentifier"; EKCalendarItem ) 

**MBS**( **"Events.Item.CalendarItemExternalIdentifier";** /\* A server-provided identifier for this calendar item. \*/  
**$EKCalendarItem**) /\* The reference to the calendar item: an event or reminder.e.g. $item \*/ 

### Parameters

| Parameter | Description | Example |
|---|---|---|
| EKCalendarItem | The reference to the calendar item: an event or reminder. | $item |

### Result

Returns ID or error.

### Description

A server-provided identifier for this calendar item.  
This identifier, provided by the server, allows you to reference the same event or reminder across multiple devices. For calendars stored locally on the device, including the birthday calendar, it simply passes through to calendarItemIdentifier.  
This identifier is unique as of creation for every calendar item. However, there are some cases where duplicate copies of a calendar item can exist in the same database, including:   
- A calendar item was imported from an ICS file into multiple calendars
- An event was created in a calendar shared with the user and the user was also invited to the event
- The user is a delegate of a calendar that also has this event
- A subscribed calendar was added to multiple accounts In such cases, you should choose between calendar items based on other factors, such as the calendar or source.

This identifier is the same for all occurrences of a recurring event. If you wish to differentiate between occurrences, you may want to use the start date.  
In addition, there are two caveats for Exchange-based calendars:   
- This identifier will be different between EventKit on iOS versus OS X
- This identifier will be different between devices for Reminders

You can later use [Events.CalendarItemsWithExternalIdentifier](EventsCalendarItemsWithExternalIdentifier.md) function to get the local identifier back.  
### See also

- [Events.CalendarItemsWithExternalIdentifier](EventsCalendarItemsWithExternalIdentifier.md)
- [Events.Item.CalendarItemIdentifier](EventsItemCalendarItemIdentifier.md)

### Example Databases

- [Mac and iOS/Events/Events Import](https://www.mbsplugins.eu/MBS-FileMaker-Plugin-Examples/Mac%20and%20iOS/Events/Events%20Import.shtml#1ScriptAnchor_)
- [Mac and iOS/Events/Events Sync](https://www.mbsplugins.eu/MBS-FileMaker-Plugin-Examples/Mac%20and%20iOS/Events/Events%20Sync.shtml#5ScriptAnchor_)

This function checks for a license.

Created 10th March 2016 , last changed 12nd December 2023

  
[Events.Item.Attendees](EventsItemAttendees.md) - [Events.Item.CalendarItemIdentifier](EventsItemCalendarItemIdentifier.md)

[HTML Version](EventsItemCalendarItemExternalIdentifier.shtml)