To edit your date of birth: Click the Edit Profile (Update Info) button at the top of your profile...
To edit your date of birth:
Click the Edit Profile (Update Info) button at the top of your profile (timeline)
Enter your birthday in the Birthday field
Save your changes
Note: We have limits in a place around the number of times you can edit your birthday. If you recently edited your birthday, you may have to wait a few days before changing it again. Learn more about our Community Standards.