How to add a calendar by iCal (ICS) link, and what to expect from it
You copy the address the calendar publishes, paste it, and from then on it reads itself. It is the standard way to bring in holidays, school or league fixtures without handing over any password.
The short answer: paste the URL the source calendar gives you, and that is it. An iCal link — sometimes written as ICS, sometimes as a webcal address — is a text file the service itself publishes with its events inside. No account, no password: whoever holds the link can read the calendar. That is what makes it right for public holidays, the school calendar, a league fixture list, a shared iCloud calendar or a published Outlook one.
Where to find the link
The wording changes per service, but the place is always similar:
- Google Calendar: calendar settings, "Integrate calendar", the iCal-format address.
- iCloud: share the calendar publicly and copy the address.
- Outlook: publish the calendar and take the ICS link, not the HTML one.
- Schools, clubs and councils: usually labelled "subscribe" or "add to my calendar".
What to expect once it is pasted
- It refreshes every quarter of an hour, not instantly. What is downloaded is kept fresh for fifteen minutes. If a match has just been moved, it can take that long to show.
- It is read-only. You cannot create or edit an event in a subscribed calendar, and that is not an application choice: the format is a publication, not an API.
- If a download fails, the last good copy is kept and the error is shown, rather than leaving your day blank.
- There are common-sense limits: up to ten calendars per account, five megabytes and ten seconds per download. One enormous calendar cannot drag the rest down.
A warning about the link itself
That link is a credential in disguise. Anyone holding it can read the entire calendar without asking permission, so it does not belong in a group chat or on a web page. We treat it accordingly: it is stored encrypted at rest and never returned to the browser; the screen only shows the host.
For the same reason we only accept public https addresses. No links to an internal network address, none with a username and password baked in, none pointing at an odd port — and every redirect is re-checked before it is followed.
When it is the wrong tool
If what you want is your own full personal calendar rather than one specific public calendar, the iCal link is a detour: connect the Google or Microsoft account and you get up-to-date reading and, with permission, writing. The link shines exactly where there is no account to connect.
Same if you expect a change to appear within the second. That is what connected accounts are for, not subscriptions.
More context in how to see Google Calendar and iCloud together, and the rest of the section in calendar and tasks. The day view lives in the console.
Frequently asked questions
- What is the difference between iCal, ICS and webcal?
- They are the same thing from different angles: iCalendar is the format, .ics the file extension, and webcal:// a prefix systems translate to https. Any of the three forms can be pasted in.
- How often does a subscribed calendar refresh?
- What has been downloaded counts as fresh for fifteen minutes. A change at the source takes at most that long to appear, and if the download fails the last good copy is kept.
- Can I edit an event in a linked calendar?
- No. An iCal subscription is a read-only publication. To create or move events you have to do it in the source calendar, or connect that account.