I've been working with Ajax for a few weeks, I used a caledarextender control and I was trying to get a date formated to "dd/mm/yyyy". But the only value i got was "03/00/2006". (Notice about "00" on month element).
To fix the problem I found this simple solution:
Just change mm to MM and that´s it!!
I noticed that is the same design in Windows Vista calendar control....