Why do I see duplicate events from a shared calendar and my own calendar?

If you see the same event appearing twice in BusyCal — once on a shared calendar (for example, a colleague's calendar, a family calendar, or a project calendar shared with you) and again on a calendar you own — this is usually because the event genuinely exists on both calendars and BusyCal is faithfully syncing both copies.

The fix is to enable View > Combine Identical Events from the BusyCal menu bar at the top of the screen. With this turned on, BusyCal automatically collapses identical copies and shows only the most appropriate one in your view, while still letting you switch to any of the other copies from the Info Panel.

This commonly happens with:

• A meeting invite delivered to more than one of your accounts (e.g. work and personal) that you both have connected to BusyCal.
• An event on a shared/family calendar that also appears on a personal calendar you own.
• Two overlapping subscriptions (such as two similar holiday calendars) that contain the same entries.
• Cross-calendar blocking events, where the original event and its blocking copy share the same title and time.

For the full criteria BusyCal uses to decide that two events are identical, how it picks which copy to display, and how to access the hidden copies from the Info Panel, see Combine Identical Events.