The Google Calendar API has a courtesy limit of 1,000,000 queries per day.
To view or change usage limits for your project, or to request an increase to your quota, do the following:
- Go to the Google Developers Console.
- Select a project, or create a new one.
- In the sidebar on the left, expand APIs & auth.
- Click APIs.
If you have enabled billing for your project, you can see the quota percentage for each API. Selecting an API takes you to a page with overview, usage, and quota information for that API. On that page, choosing Quota lets you view and change quota-related settings. Choosing Usage provides you with usage statistics as well as response code and method information.