# Calendar and time zones

Pass `time_zone` (an IANA name such as Africa/Johannesburg) on calendar tools; without it the workspace's time zone applies. Times are ISO 8601: with an offset, or without one to mean `time_zone`; all-day events use dates.

## Availability
`calendar_get_free_busy` covers all your calendars and, where the provider can see them, other people. `calendar_find_meeting_times` suggests slots free for everyone; pass `working_hours_only: true` to keep them inside working hours (by default they can fall at night or at weekends).

## Changes that notify people
Creating an event with attendees sends invitations; changing or deleting one sends updates or cancellations. These count as sends and can be held for approval.