I have already visited this question Is There a Workaround for lack of Olsen TZ TZID Format in ICS File
I was able to understand why Outlook messes up with the times of two events in same timezone but in daylight save mode eg:
BEGIN:VCALENDAR
VERSION:2.0
PRODID: // Some staff
METHOD:PUBLISH
X-WR-CALNAME:Adak Events
BEGIN:VEVENT
UID:ev1
DTSTART;TZID=America/Adak:20140619T120000
DTEND;TZID=America/Adak:20140619T130000
DTSTAMP:20150409T105433Z
TRANSP:OPAQUE
X-MICROSOFT-CDO-BUSYSTATUS:BUSY
SUMMARY:Adak Event
LOCATION:Adak
DESCRIPTION: Summer
END:VEVENT
BEGIN:VEVENT
UID:ev2
DTSTART;TZID=America/Adak:20141219T120000
DTEND;TZID=America/Adak:20141219T130000
DTSTAMP:20150409T105433Z
TRANSP:OPAQUE
X-MICROSOFT-CDO-BUSYSTATUS:BUSY
SUMMARY:Adak Event
LOCATION:Adak
DESCRIPTION: Winter
END:VEVENT
END:VCALENDAR
But my real question what happens when I want to have multiple events in multiple timezones? I have seen that the solution to specify a timezone is:
BEGIN:VTIMEZONE
TZID:Europe/Prague
BEGIN:DAYLIGHT
DTSTART:20140330T030000
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=3
TZNAME:CEST
END:DAYLIGHT
BEGIN:STANDARD
DTSTART:20141026T020000
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
TZNAME:CET
END:STANDARD
END:VTIMEZONE
But when I have multiple timezones in a single ICS? How can I handle such a thing for Outlook?
PS: In other mail apps TZID did the job so far
Yes, you can define multiple time zones. And dates in the VEVENT part can refer to these multiple time zones.