[Users] vCalendar default timezone?

[Dave Howorth]

On Fri, 4 Dec 2020 18:38:26 -0500
Pierre Fortin <pf at pfortin.com> wrote:

> Hi, 
> 
> It's been a LONG time since I last received an ICS file. 
> 
> This one appeared to change my 2pm appointment to 9am...
> 
> I don't see a setting for timezone in vCalendar; does it assume GMT
> if a received ICS file does not contain a TZID field? 
> 
> Received ICS file:
> >BEGIN:VCALENDAR
> >PRODID:-//Flo Inc.//FloSoft//EN
> >BEGIN:VEVENT
> >DTSTART:20201207T140000
> >DTEND:20201207T150000
> >LOCATION:R & N Motor Company
> >DESCRIPTION;ENCODING=QUOTED-PRINTABLE:Appointment Reminder
> >SUMMARY:Your appointment is coming up soon!
> >PRIORITY:3
> >END:VEVENT
> >END:VCALENDAR  
> 
> See screenshot...
> 
> Am I missing something or should I file an enhancement request to
> select default TZ as GMT or local? Local would seem the more
> reasonable default.

Refer to https://tools.ietf.org/html/rfc5545
A date-time without timezone is 'floating'. It is to be interpreted
relative to whatever timezone the person or persons affected by the
event are in. (Could be multiple timezones if multiple people). The
meaning of such an event is not uniquely defined.

So the screenshot you attached has used some other information not
present in the ICS file to determine what timezone to display. Nobody
can tell whether whatever it was made the right decision.

> Thanks,
> Pierre