Google Sync Error 403: Rate Limit Exceeded

If you receive a 403 Forbidden or Rate Limit Exceeded error when syncing with Google Calendar, it means Google has temporarily blocked access to your account due to excessive server requests.

What Causes This?

Google imposes strict quotas on how many times an application can connect to their servers within a specific timeframe. This can happen if:

• You have a very large number of events or calendars.
• You are syncing the same Google account on multiple devices simultaneously.
• You have triggered a "Sync" or "Refresh" manually too many times in a short period.
• Third-party plugins or scripts are interacting with your calendar excessively.

How to Fix It

1. Wait it out (Most Important)

The block is temporary and controlled entirely by Google. In most cases, it will reset automatically after 4 to 24 hours. Do not remove and re-add your account, as this will trigger a full re-sync and likely prolong the block.

2. Reduce Sync Frequency

To prevent this from happening again, reduce how often BusyCal checks for changes:

1. Go to BusyCal > Settings > Accounts.
2. Select your Google account.
3. Change the Refresh interval to a longer duration (e.g., every 15 or 30 minutes, or "Manual").
4. If "Push" is enabled, try disabling it temporarily if you experience frequent rate limits.

3. Check Other Devices

If you have BusyCal (or other calendar apps) running on multiple Macs, iPads, or iPhones, ensure they aren't all trying to sync a massive amount of data at once.

4. Optimize Your Calendars

If you subscribe to many heavy public calendars (like "Phases of the Moon" or complex holiday calendars) via Google, consider unsubscribing from ones you don't need, as they contribute to your API usage quota.