Most Google Calendar users have a subscribed 'holidays' calendar automatically. When you connect this to a scheduling tool, those holidays can auto-block bookings — saving you from the annual 'wait, July 4th isn't a booking day' cleanup.
The problem in concrete terms
Holiday + OOO Calendars sounds like an edge case until it isn't. The moment your booking page offers a slot that's actually taken on one of your other calendars, you double-book yourself. The pattern is deterministic: sooner or later, it happens. Multi-calendar checking eliminates the pattern.
How to set it up in Cal Clear
Cal Clear supports unlimited Google account connections on the free tier. In Settings → Calendars, click 'Connect another account,' complete the Google OAuth flow, and that calendar is now part of your availability check. No paid tier required, no user-count limit.
What to check before you go live
Book a test appointment across each connected calendar's busy times to verify the conflict check actually blocks them. Spot-check at least one edge case per account (a recurring event, an all-day event, a multi-day event). If anything slips through, the tool isn't wired right — stop using it for client bookings until fixed.
Part of the multi-calendar scheduling pillar guide.
Frequently Asked Questions
How many calendars can I connect to Cal Clear?
Unlimited on both free and Pro tiers. Most users connect 2-5 accounts; there's no hard cap.
Will clients see my other calendar's event names?
No. Cal Clear uses Google's freeBusy API which returns busy intervals only — no event titles, attendees, or descriptions.
Unlimited calendars on every booking, free
Cal Clear checks every connected Google account on every booking-page request. Free forever, no tier gating.