Help, from the people who build it.

Open the spreadsheet you want to sync in Google Sheets™, then choose Extensions → Cellendar → Set up sync. The setup sidebar opens on the right. After setup, use Extensions → Cellendar → Check rows to preview changes, or Sync now to apply them.

If you don't see Cellendar under Extensions, reload the spreadsheet. In a Google Workspace account, your administrator may need to allow the add-on first.

Only two: a title and a start date (or date and time). Everything else is optional: end date, start and end time, all-day, time zone, location, description, guests, colour, calendar, and a delete marker. Cellendar suggests a mapping from your column headers, and you can change any of it.

Read the row's Sync status cell: it says what went wrong, for example “⚠ End before start” or “⚠ Start date is not a date”. Fix the cell and run Check rows again. Rows with problems are skipped, and the rest of the sheet still syncs.

If the status starts with “✗ Calendar error”, the problem came from Google Calendar™. Wait a minute and run Sync now again. Cellendar picks up where it stopped and won't create duplicates. If the error keeps coming back, email us the row number and the full status text.

By default, the spreadsheet's time zone (File → Settings → Time zone in Google Sheets), not your computer's. To use a different time zone for some rows, add a time zone column with IANA names such as Europe/Berlin or America/New_York. Common city names like “Berlin” are recognised too, and the check screen warns you when it has to guess.

Because that's how people write dates. In Cellendar, an all-day event from 12 to 16 lasts through the 16th. If you leave the end date empty, the event lasts one day.

Not unless you turn it on. By default Cellendar adds guests to events without sending invitations or update emails. You can change this in the setup or in Settings.

There are two kinds of limits:

• During the beta there is no row limit of our own; only Google's daily limits apply.
• Google's limits, which apply to every add-on: Google currently allows about 5,000 new calendar events per day for a personal account and 10,000 for a Google Workspace account, limits how many requests can be made per minute, and caps how long an add-on can run at once. Google may change these limits.

For large sheets, Cellendar works in batches and continues where it left off. If you reach a Google limit, the affected rows say so in their status; run the sync again later (Google's daily limits reset within 24 hours).

Not automatically. To delete an event, put a delete marker (such as x or delete) in the delete column: the event is removed and the row stays, with the status “✓ Deleted”. If you remove rows entirely, Check rows lists their events and lets you choose whether to delete them. Deletions always need your confirmation.

Go to myaccount.google.com/connections, choose Cellendar and remove its access. To uninstall it as well, in Google Sheets open Extensions → Add-ons → Manage add-ons. Events already created stay in your calendar until you delete them. See the Privacy Policy for how to delete your license record.

No. Your spreadsheet and calendar contents are processed inside Google's systems. During the beta Cellendar has no server of its own, so nothing is sent to us. Details are in the Privacy Policy.

Email us within 14 days of your purchase and we'll refund it in full. See the Terms of Service.