# Importing and managing events from third-party calendars
<a name="third-party-events"></a>

As an alternative to creating events directly in the Amazon Systems Manager console, you can import an iCalendar (`.ics`) file from a supported third-party calendar application. Your calendar can include both imported events and events that you create in Change Calendar, which is a tool in Amazon Systems Manager.

**Before you begin**  
Before you attempt to import a calendar file, review the following requirements and constraints:

Calendar file format  
Only valid iCalendar files (`.ics`) are supported.

Supported calendar providers  
Only `.ics` files exported from the following third-party calendar providers are supported:  
+ Google Calendar ([Export instructions](https://support.google.com/calendar/answer/37111))
+ Microsoft Outlook ([Export instructions](https://support.microsoft.com/en-us/office/export-an-outlook-calendar-to-google-calendar-662fa3bb-0794-4b18-add8-9968b665f4e6))
+ iCloud Calendar ([Export instructions](https://support.apple.com/guide/calendar/import-or-export-calendars-icl1023/mac))

File size  
You can import any number of valid `.ics` files. However, the total size of all imported files for each calendar can't exceed 64KB.  
To minimize the size of the `.ics` file, ensure that you are exporting only basic details about your calendar entries. If necessary, reduce the length of the time period that you are exporting.

Time zone  
In addition to a calendar name, a calendar provider, and at least one event, your exported `.ics` file should also indicate the time zone for the calendar. If it does not, or there is a problem identifying the time zone, you are prompted to specify one after you import the file.

Recurring event limitation  
Your exported `.ics` file can include recurring events. However, if one or more occurrences of a recurring event had been deleted in the source calendar, the import fails.

**Topics**
+ [Importing events from third-party calendar providers](change-calendar-import.md)
+ [Updating all events from a third-party calendar provider](change-calendar-import-add-remove.md)
+ [Deleting all events imported from a third-party calendar](change-calendar-delete-ics.md)