Hello,

Total novice here, I'm afraid.

When creating an all day event, using a start time and then converting to all day event, I can successfully generate an ics file containing multiple such events.

However, this file doesn't validate and causes some problems eg importing natively into android calendar.

The validation issue is because there is no DTSTAMP property in the VEVENT

Looking at the source code (again, be gentle please, novice) this seems to be set when (and only when) the event.created thingy is set.

However, this is a MANDATORY entry for this type of event (all day, anniversary or basically any VEVENT).

See here:
Linky

Example ics file without DTSTAMP

PRODID:ics.py - http://git.io/lLljaA
VERSION:2.0
BEGIN:VEVENT
DTSTART;VALUE=DATE:20191002
SUMMARY:Lazy Bed Day
TRANSP:OPAQUE
UID:ad7a84a7-8d24-41c9-a4cd-26cb2da14e11@ad7a.org
END:VEVENT
BEGIN:VEVENT
DTSTART;VALUE=DATE:20191001
SUMMARY:Busy Frantic Day
TRANSP:OPAQUE
UID:be265bab-c7a7-4b09-b20e-1c7419b94d8d@be26.org
END:VEVENT
END:VCALENDAR

Obvs it would be nice if this mandatory entry was included by default.

Ta