If you've ever tried to add an external calendar to Google Calendar or Outlook, you've probably run into both options: import and subscribe. Most calendar apps don't explain the difference well, and picking the wrong one leads to a calendar that goes stale or events that mysteriously appear twice.
Here's what each one actually does.
Importing a calendar
Importing a calendar means you're taking a snapshot of events from a file — usually a .ics file — and copying them into your calendar at that moment.
After the import, those events are yours. They live in your calendar like any event you created manually. The connection to the source is severed. If the source calendar changes — someone reschedules a game, the school adds a new holiday — your calendar doesn't know. You'd have to import the file again to get the update, and then you'd likely end up with duplicate events.
When importing makes sense:
- One-time events that won't change (a festival lineup, a conference schedule)
- You want to edit the imported events yourself
- You're migrating your own calendar from one app to another
Subscribing to a calendar
Subscribing to a calendar means you're connecting to a live URL — called an iCal feed or calendar subscription URL. Your calendar app periodically checks that URL for updates and syncs any changes automatically.
Subscribed events appear in your calendar but they're read-only — you can see them but can't edit them from your end (since they're owned by the source). If the source updates an event, the change shows up in your calendar the next time it syncs, usually within a few hours to a day.
When subscribing makes sense:
- Recurring schedules that change over a season (sports, school, recurring events)
- You want hands-off updates without re-importing anything
- You're sharing a calendar with others and everyone needs to stay in sync
What is an iCal URL?
An iCal URL (sometimes called a calendar subscription link or .ics feed) is a web address that points to a live calendar file. It looks something like this:
https://example.com/calendar/events.ics
or
webcal://example.com/schedule.ics
Any calendar app that supports subscriptions — Google Calendar, Apple Calendar, Outlook — can follow this link and display the events in it. The webcal:// format is equivalent to https:// for calendar purposes; most apps accept either.
The key property of an iCal URL is that the file at that address can change. The person who controls it can add events, update details, or remove events, and anyone subscribed to the URL sees those changes automatically.
A real example of why this matters
Say your kid's soccer league posts the season schedule as a PDF in August. You import the .ics file your team manager sent and the games appear in your calendar.
Then in October, two games get rescheduled due to field conflicts. The team manager updates the master schedule. But since you imported rather than subscribed, your calendar still shows the old times. You show up at the wrong time. The import approach broke down exactly when it mattered most.
If you had subscribed to a calendar URL instead, those reschedules would have appeared in your calendar automatically. No action required on your end.
How to subscribe in each major calendar app
Google Calendar
- Open Google Calendar on the web (not the mobile app — subscriptions require the browser)
- Click + next to "Other calendars" in the left sidebar
- Select From URL
- Paste the iCal URL and click Add calendar
Apple Calendar (iPhone)
- Open Settings → Calendar → Accounts → Add Account → Other
- Tap Add Subscribed Calendar
- Paste the URL and tap Next, then Save
Outlook (web)
- Open Outlook Calendar at outlook.com
- Click Add calendar
- Select Subscribe from web
- Paste the URL and click Import
Outlook (desktop)
Go to File → Open & Export → Open Calendar (Windows) or File → New Calendar Subscription (Mac), paste the URL, and confirm.
How CalHelper fits in
CalHelper creates subscribable iCal feeds from any schedule source — a PDF, a photo, or pasted text. Instead of importing a one-time file, you get a live URL that you and anyone else can subscribe to.
This is useful when the schedule you receive isn't already in calendar format. A school sends home a paper calendar. A coach photographs the game schedule on a whiteboard. An event organizer emails a PDF agenda. CalHelper extracts the events and gives you a subscription URL — the same technology that powers live sports and school district calendars, available for any schedule you have.
Event coordinators and schedule managers use this to give attendees a calendar they can subscribe to rather than a file they have to manually import and maintain. See how it works at /use-cases/event-coordinators.
The short version: if the schedule might change, subscribe. If it's a one-time snapshot, import. And if the schedule isn't in a calendar-ready format at all, CalHelper can turn it into one.