The side-project calendar exists in a different time zone from your day-job calendar — literally, it lives in 'evenings and weekends' rather than standard business hours. Double-booking happens when a side-project meeting ends up overlapping with family time, a dentist appointment, or travel. Multi-calendar checking is the only solution that catches this reliably.
The problem in concrete terms
Side-Project Calendar Conflicts 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.