Facilities teams that manage room and space bookings through Google Calendar deal with some of the most heavily-used shared calendars in any organisation. A busy office with 10 meeting rooms might process hundreds of bookings per week, generating thousands of calendar entries per year.
At minimum, clear all room booking calendars annually — typically at the start of a new calendar year or financial year. This removes 12 months of historical bookings while preserving future reservations already made.
For very high-volume venues (conference centres, co-working spaces, campus buildings), a quarterly clearing cycle keeps calendars manageable and prevents performance issues in booking system integrations.
Test a booking after clearing. After each maintenance cycle, make a test booking through your room booking system and verify it appears correctly in the Google Calendar. This confirms the integration is functioning normally after the clean-up.
When rooms are renamed, reconfigured, or repurposed, clearing historical bookings from the old configuration is a practical step. A room that was "Meeting Room 3" is now "The Blue Room" — clearing its historical bookings avoids confusion about which configuration past entries refer to.