Importing an event file and subscribing to a calendar are different actions. Google Calendar documents both workflows separately. If you imported a file, do not assume that later edits to the organiser's calendar will automatically reach that imported copy.
Reconstruct how you added it
Imagine a club sends a season schedule, then changes the start time of one session. Did you download and import a file, or add the organiser's calendar through a subscription or published URL? Look at the original instructions and the calendar list before repeating the import.
Ask the organiser which method they intended and which source is current. A second import can complicate the comparison if it creates another set of events. Keep the existing entries identifiable until you understand which ones belong to which source.
Check one changed event
- Compare its date, time and stated time zone.
- Check the calendar it belongs to.
- Compare a recurring event with its relevant occurrence.
- Confirm that you still have access to the intended shared calendar.
Do not promise an exact refresh interval without the service's current documentation. If you only need a one-time snapshot, an import may be sufficient. If the organiser will keep changing the timetable, choose an authorised updating arrangement and test a known change before relying on it for the whole season.