If you’d like a comprehensive and correct list of all events in your Moodle calendar in an external calendar you can use the subscription function. Here’s how to subscribe to the Moodle calendar. Note this does not allow you to set reminders in the events.
Instructions:
Go to the user menu at the top of the page and click on "Calendar"
Scroll down to "Import or Export calendars"
Click the button "Export Calendar".
Select "All events" and "Custom Range", then click "Get calendar URL".
As you can see, the custom range syncs until the next year, however, once the sync is set the dates and events will continue to update indefinitely. Copy the URL.