To protect users and domains from abusive behavior, Google sets limits for Google Calendar use.
These limits are above the activity level of typical Calendar users, so most users won't exceed them. If you do exceed these limits, however, your Google Calendar might become read-only for a few hours. You can still view events when your calendar is read-only, but you can't create or edit events.
Note: Calendar keeps events indefinitely as long as the user does not delete them.
Errors related to use limits
If you exceed Calendar use limits, you might get messages such as:
Unable to save event—You reached the limit for the number of events you can edit.
Calendar usage limits exceeded—Results from an API call.
There was a problem saving your changes. Please try again in a few minutes—Message is followed by more information describing what limit was reached.
Avoid exceeding limits
To avoid exceeding Calendar limits, follow these guidelines.
Create too many events
Create too many calendars
Send too many invitations to external guests
Email too many guests via Google Calendar events
Share calendars with too many users
*This number is true only if a user’s limits are fully replenished. If a user does any actions in this table regularly, then the actual use limit might differ.
Additional use limits for free & trial accounts
Some Calendar use limits are automatically increased when your domain has cumulatively paid at least USD $100 (or equivalent), and at least 60 days have passed since achieving that payment threshold. If you purchased your domain from Google, the amount required to increase your limits is USD $100 plus the cost of your domain.
Important: Calendar use limits are not increased during your trial period. Your account must have started a subscription and ended the trial period before these limits can be increased.