Getting started
ICalSync reads an external iCal feed and writes the events into a Google Calendar you own, keeping the two in step in realtime. This page takes you from install to first synced event.
Before you start
You need the iCal (.ics) URL of the calendar you want to bring in, and
permission to install add-ons on your Google account.
1. Install the add-on
Open the ICalSync listing on the Google Workspace Marketplace and choose Install. Google will show you the permissions the add-on requests — calendar access, so it can create and update the events you ask for. Accept, and ICalSync appears in the side panel of Google Calendar.
Administrators installing for a whole domain should use the same listing and choose the domain-wide install; everyone in the organisation gets the add-on without acting individually.
2. Add a calendar feed
Find the feed URL in the system that owns the schedule. It usually sits under a
menu called share, publish, subscribe or export, and ends in .ics. Paste it
into ICalSync and give the connection a name you will recognise later.
| Source | Where the feed URL usually lives |
|---|---|
| Another Google Calendar | Settings → Integrate calendar → Secret address in iCal format |
| Outlook / Microsoft 365 | Calendar settings → Shared calendars → Publish a calendar |
| Booking & scheduling tools | Look for “iCal feed”, “Subscribe” or “Calendar export” |
3. Choose the destination
Pick which of your Google Calendars the events should be written into. A dedicated calendar per feed is the setup we recommend: you can toggle it on and off, give it its own colour, and share it without exposing anything else.
4. Verify the first sync
Open the destination calendar and find an event you recognise. Then change something on the source — move a booking by an hour — and watch it follow through. Once you have seen one change land, the connection needs no further attention.
Troubleshooting
Nothing appeared after I added the feed
Open the URL in a browser. If it downloads a text file starting with
BEGIN:VCALENDAR, the feed is valid and the problem is the destination
calendar. If it asks you to sign in, the feed is private and needs a public or
secret address instead.
Events are duplicated
Usually the same feed is both subscribed through Google’s From URL option and synced through ICalSync. Remove the subscription and keep the sync.
Times are off by an hour
Some systems publish feeds without timezone information. Check the timezone on both the source system and the destination Google Calendar before assuming the sync is at fault.