Hi ehsankhan,
This is not possible with the date pickers. The date pickers require all 3 date parts (day, month & year) in order to calculate DateTime values correctly.
You might want to look into using two DropDownList controls, or one DropDownList (Months) and a TextBox (Year).
Hope this helps answer your question.
Thanks,
Geoffrey McGill
----------------------------------------
Coolite Inc.
Email: support [at] coolite [dot] com
Phone: +1(888)775-5888