Auto-busy blocking across calendars (Pro)
Posted: June 10, 2026 · 3 min read
What auto-busy blocking does
One client books you at 2pm. Your other clients still see that slot as open, and one of them grabs it. Now you have a conflict that was entirely preventable.
Auto-busy blocking closes that gap. When a new meeting lands on one of your calendars in an open slot, manyCalendars places a matching Busy block on each of your other calendars. Anyone checking your availability on those calendars sees the slot as taken. Nobody double-books you.
This is a Pro feature. Like everything in manyCalendars, it runs entirely in your browser. No cloud sync, no server in the middle, and your calendars are read and merged on your device, not in our cloud.
Step 1: Turn it on
Click the manyCalendars icon in your toolbar and open Settings.
Scroll to the Auto-busy blocking section and switch the toggle on.
Pick which calendars should receive Busy blocks. These are your manual calendars: the ones where you can create events directly. Calendars that are read-only, such as a feed you only sync, can trigger blocks on others but cannot receive them.
That is the whole setup. From now on, when manyCalendars detects a new meeting in a slot that was open, it creates a matching Busy block on every target calendar you selected.
Step 2: Customize the Busy title
By default, every block is titled "Busy". You can change this in the Busy block title field in the same settings section.
The block carries no details from the source meeting. No attendee names, no meeting subject, no client information. Just the title you choose and the time range. That is deliberate.
If you want different titles on different calendars, set a per-calendar title when you select your target calendars in Step 1.
Step 3: Let cleanup handle the rest
Every block manyCalendars creates carries a hidden marker, so it only ever touches its own blocks. Events you created yourself are never modified or removed.
If the source meeting is cancelled, the matching Busy blocks are removed on the next scan. If the meeting moves to a new time, the blocks move with it. You do not have to clean anything up by hand.
Deleted a block manually? manyCalendars treats that as intentional and will not recreate it for the same source meeting.
Good to know
Blocks only go into open slots. If the new meeting overlaps something that already exists, manyCalendars flags it as a conflict instead, with the usual red outline and conflict count. Auto-busy blocking prevents future double-bookings; conflict detection catches existing ones.
Scans drive the timing. Blocks are placed when manyCalendars next reads your calendars, so keep your calendar tabs available the way you normally would.
Auto-busy blocking is part of Pro, alongside unlimited calendars, Tab Sync, and Privacy Mode. If you are on the free plan, you can upgrade to Pro on the checkout page. For everything else, browse all tutorials in the Help Center.