googleCalendar.queryFreeBusy returns busy intervals without event details for people, rooms, or Google Groups.
Example
Inputs
Providecalendars as an array of 1–50 exact calendar titles, IDs, or Google Group IDs. You must also provide timeMin and timeMax in RFC 3339 format, and the end must follow the start. timeZone optionally controls the response timezone. Second argument { account } selects the Google Account.
Output
errors. Google can return partial results when it can’t access a calendar or expand a group.