Description of Problem:

The birthdays from the Contacts all begin at 2am and end at 2am the next
day, i.e. for each birthday I have two "all day events" in my calendar.

It seems that it's 2am because I have my timezone set to "Europe/Berlin"
and birthdays seem to be UTC. If I change my timezone to
"Australia/Darwin", birthdays begin and end at 0930.

However, I haven't found an option to 

  (a) assign a timezone to birthdays or
  (b) say that birthdays are relative to my chosen timezone


Steps to reproduce the problem:
1. Create a contact with birthday 23/06/2004
2. In Calendar, select the calendar Contacts > Birthdays & Anniversaries to 
   display
3. Select timezone to be "Europe/Berlin"


Actual Results:
  The birthday shows as an event beginning 23/06/2004 02:00 ending
24/06/2004 02:00.
  The calendar widget on the right highlights both 23/06/2004 and 24/06/2004.


Expected Results:
  The birthday shows as an event beginning 23/06/2004 00:00 ending
23/06/2004 24:00.
  The calendar widget on the right highlights only 23/06/2004.


How often does this happen? 
  always