Issue with iOS Safari Handling Updates in .ics Files

I have an endpoint that generates a .ics file. From my mobile app, I open the browser (Safari) and retrieve the .ics file. In Safari, the events are displayed as expected, and I can use the "Add All" button to add them to the calendar. After clicking "Add All," I can select the desired calendar, and the events are successfully added (see screenshots 1 and 2 below).

Here’s the initial .ics file response:

BEGIN:VCALENDAR
VERSION:2.0
CALSCALE:GREGORIAN
PRODID:NAME
BEGIN:VEVENT
DTSTAMP:20250101T195917Z
DTSTART:20250102T131600
DTEND:20250102T142500
SUMMARY:My Event 1
UID:unique-uid1
LAST-MODIFIED:20250101T155715Z
DESCRIPTION:Description
SEQUENCE:1
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20250101T195917Z
DTSTART:20250103T131600
DTEND:20250103T135600
SUMMARY:My Event 2
UID:unique-uid2
LAST-MODIFIED:20250101T155715Z
DESCRIPTION:Description
SEQUENCE:1
END:VEVENT
END:VCALENDAR

Later, I updated the .ics file with new event details:

BEGIN:VCALENDAR
VERSION:2.0
CALSCALE:GREGORIAN
PRODID:NAME
BEGIN:VEVENT
DTSTAMP:20250102T195917Z
DTSTART:20250104T131600
DTEND:20250104T142500
SUMMARY:My Event 1 Update
UID:unique-uid1
LAST-MODIFIED:20250104T155715Z
DESCRIPTION:Description
SEQUENCE:2
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20250102T195917Z
DTSTART:20250105T131600
DTEND:20250105T142500
SUMMARY:My Event 2 Update
UID:unique-uid2
LAST-MODIFIED:20250102T155715Z
DESCRIPTION:Description
SEQUENCE:2
END:VEVENT
END:VCALENDAR

I updated everything according to the iCalendar documentation:

  • UID remained unchanged
  • SEQUENCE has been updated
  • DTSTAMP has been updated
  • LAST-MODIFIED has been updated

However it seems like that Safari can't handle updates on events. In the preview we can see the changes, but when I click on "Add All" button, nothing happens. The same behavior is working with other calendars like Outlook (web view) or Google Calendar.

My Questions:

  • Is there a property missing from my .ics file that is necessary for iOS Safari to handle updates?

  • Is Safari not designed to handle event updates in this way?

  • Should I consider moving to a subscription-based solution to manage updates more reliably?

Any insights or suggestions would be greatly appreciated!

Issue with iOS Safari Handling Updates in .ics Files
 
 
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