Google / Android: Open Google Calendar in a computer browser. Beside “Other calendars,” choose + → From URL, paste the address below, and add it. Then use the same Google account in your phone’s Calendar app and enable this calendar. Google’s mobile app cannot add a URL subscription directly.
iPhone: Tap the Apple subscription button. If it does not open Calendar, open Calendar → Calendars → Add Calendar → Add Subscription Calendar and paste this address.
Subscriptions update on your calendar provider’s refresh schedule; changes may take time. Check this page before traveling to a meeting. Downloaded files and individual “Add to Google” copies do not stay synchronized. A calendar listing does not reserve a seat in a delegation.