ICS Calendar Files and Links: Import, Subscribe, or Sync?

Import an ICS file when you want a one-time copy of events. Subscribe to an ICS link when you want to follow a schedule that somebody else updates. Use a synchronization tool when events from that source need controlled copies in another calendar.

Websites often label all three actions “Add to calendar.”

Before you click, check whether you are downloading a file or following a continuing feed. That choice determines how later changes reach you.

A file is a snapshot

An ICS file contains calendar information at the time it was created. It can hold one appointment, a conference program, or years of events.

Importing the file places those events in the calendar you choose. If the publisher later changes the program, your imported events do not automatically learn about the changes. Google's import guide explains how to select a file and destination calendar.

For a one-off event that is unlikely to change, this is convenient. For a changing university timetable, importing a fresh file every week can leave old times and duplicates behind.

Before a large import, create a separate temporary calendar and import there first. That gives you a clear way to review the results and remove the batch if you chose the wrong file. Avoid importing directly into a busy work calendar before checking the contents.

A link follows a published schedule

A subscription link points to a feed maintained by the publisher. Your calendar periodically retrieves it and displays the events.

In Google Calendar on a computer, use the plus button beside Other calendars and choose From URL. In Outlook on the web, use Add calendar and Subscribe from web. In Calendar on Mac, use File and New Calendar Subscription.

Sports schedules, public holidays, and class schedules work well as subscriptions because one publisher can maintain the source. Subscribers usually cannot edit those events. Report a wrong class time to the publisher; the subscription entry is read-only.

Updates are not necessarily immediate. Microsoft warns that subscription changes can take more than 24 hours to appear. That makes a feed less suitable as the only notice of an urgent change.

Keep the URL private when the schedule is private

Some calendar links contain a secret address rather than asking each viewer to sign in. Treat that address like access to the schedule. Do not paste it into a public support forum, screenshot, or team document unless everyone there should have the information.

If your family calendar includes home addresses and children's activities, use authenticated sharing where available. Publishing the calendar to get it into another app can expose those details to anyone who receives the link.

If you have already shared a link too widely, stop or reset publication using the source provider's controls. Removing the subscription from your own app does not invalidate the address for other people.

Seeing the feed does not always block bookings

A subscription can be visible beside your work calendar without contributing to the availability checked by coworkers or a booking page. The receiving system must actually consider it.

For example, a class schedule in a different color can remain separate from the calendar your employer checks. Open the work scheduling screen to see whether lectures block meetings. If they do not, review the options for secondary calendars and work availability.

Copying a feed through Avum

Avum accepts ICS links as read-only sources. You can use a Sync Rule to copy relevant events into a writable Google, Outlook, iCloud or compatible CalDAV calendar, choosing how much detail the destination receives.

The original feed remains read-only. Avum cannot send your edits back through an ICS link, and it cannot discover a source change before the publisher makes it available. A CalDAV calendar can receive copies only if its server and your account permissions allow Avum to write to it.

If a simple subscription gives you everything you need, use it. Automatic copies are helpful when another calendar needs the occupied time or a different version of the event details.

When checking the first result, compare an event's date, time zone, and availability with the source. When the publisher changes an event, wait for the subscription or copying process to update it; importing another file creates a separate transfer.

Removing an import or subscription

To stop following a feed, remove its subscription. To remove imported events, delete the imported batch or its separate calendar. When switching from a file to a feed, choose the connection you want to keep, then remove only the old imported set so the calendar does not show both.

Ready to put calendar feeds to work? Start your free 30-day trial with Avum today.