Go to https://www.facebook.com in your preferred browser. This will load your News Feed if you're already logged into Facebook. If you aren't already logged into Facebook, enter your email address (or phone number) and password before continuing. Your first name should be in the upper-right side of the Facebook page. Click it to go to your profile. It's below and to the right of your profile picture. This tab is on the left side of the About page. It's below the "BASIC INFO" heading. To edit your birthday:  Select either your birthday or your birth year. Click Edit on the right side of the page. Click the month, day, or year that you want to change. Click a new month, day or year. Repeat this process for each part of your birthday that you want to change. It's at the bottom of the window you're in. Doing so will update your birthday in your profile's "About" section.
फेसबुक वेबसाइट पर जायें: आपके नाम पर क्लिक करें: About पर क्लिक करें: Contact and Basic Info बर्थ डेट को बदलने के लिए स्क्रॉल डाउन करें: Save Changes पर क्लिक करें: