This is a very simple application, which adds birthdays assigned to your contacts also to your calender, which Windows Mobile doesn’t do automatically.

Changes:

[+] Added ability to customize reminder time for birthday alerts.
[#] Fixed birthday start date (it now starts the event on the contact’s birthday and shows their age on the event subject)
[#] Fixed bug where events couldn’t be edited because of incorrect end time
[#] Fixed other minor bugs

http://forum.xda-developers.com/showthread.php?t=529857