"Because doodles are such a fun part of the search experience, we thought we'd share a fun little way Google will help celebrate your birthday. When you include your date of birth on your Google profile, you may notice a special treat on the Google homepage on your birthday (be sure to sign in). Click on the doodle for another birthday surprise," informs the Google blog.
To change your birthday, go to your profile, click on "Edit profile" and select the "Contact info" tab. The tab lets you enter some information that can be shared with your contacts.
{ via Blogoscoped Forum }