No events being shown: "invalid date-time value" - for EXDATE at least

[nicobo]

Steps to reproduce

1. Create an event with an EXDATE (haven't tested with other fields types)
2. Extract the calendar with the event from Android with Simple-Calendar
3. Import the .ics file into NextCloud
4. The import fails with (in Firefox console) Error: invalid date-time value: "2014-11-13T::

Expected behavior

The ICS calendar file is imported OR the error is catched / explained

Actual behaviour

Nothing get imported and the error is not displayed to the user (except if you look at the console)

Calendar app version

4.1.0

CalDAV-clients used

DAVx5

Browser

Firefox

Client operating system

No response

Server operating system

No response

Web server

None

Database engine version

None

PHP engine version

None

Nextcloud version

Nextcloud Hub 3 (25.0.1)

Updated from an older installed version or fresh install

Fresh install

List of activated apps

No response

Nextcloud configuration

No response

Web server error log

No response

Log file

No response

Browser log

No response

Additional info

Sorry I really don't have time to gather all the detailed informations, but this is just a copy of #376, because I confirm this is still not fixed as of NextCloud 25.0.1.

Maybe this bug has just not been fixed for all date fields ; I've had the problem with EXDATE, probably due to my Android app not exporting correctly.

I could fix the .ics file by manually replacing all EXDATE: with EXDATE;VALUE=DATE: and could import it into NextCloud.
It can be done easily with any text editor with search & replace feature.

So to be clear I had this in my exported ICS :

EXDATE:20141113

And I could make it work by replacing with :

EXDATE;VALUE=DATE:20141113

[tcitworld]

We need to add a repair step to catch such issues: https://github.com/nextcloud/calendar-js/tree/main/src/parsers/repairsteps/icalendar