Here's what's going on:
1) Server set at GMT
2) User can select timezones in calendar events
3) Bottom left of Zimbra web client showing correct time (which is Atlantic)
4) Calendar event is created for 7:30AM with Atlantic Time chosen
5) Calendar shows event at 9:30AM
6) Time zone changed to Eastern
7) Calendar shows event at 8:30AM
8) Time zone changed to Central
9) Calendar shows event at 10:30AM (what!?)
I tried changing the timezone on the server. It had zero effect. So then I set it back to GMT and removed the user's option of selecting a timezone in calendar events. The result was that a 7:30 event shows up as 11:30AM.
Then I ran
which showed the user's timezone as Pacific. So I changed it to Atlantic with the following
zmprov ga username | sed -n 's/^zimbraPrefTimeZoneId: //p'
I then created a 7:30AM calendar event. It showed as 11:30AM again. I changed the user's timezone to GMT at a 7:30 event still showed as 11:30.
zmprov ma username zimbraPrefTimeZoneId "(GMT -4:00) Atlantic Time (Canada), Caracas, La Paz"
I have tried Firefox, Safari, and IE on OS X and WinXP. Same results. Any ideas?