Changing birthday on your Facebook profile is a simple task and here’s how you can do that on PC and Android:
Sign into Facebook.
At the top, you can find “Profile” (your name) which is between “Search Box” and “Home.” Hit it.
Now, click on “About” which you can find between “Timeline” and “Friends.”
Under the “About” section, you can see “Contact and basic info.” Hit it.
Now, under “Basic Information,” you can see “Date of birth,” “Year of birth,” and “Gender.”
Hover your mouse over the “Date of birth.” Click on “Edit” link.
Make the changes to the date, month and year as per your liking by opening the corresponding drop-down list.
Now, select “I confirm my age is X” (X is your age), and then hit the “Save Changes” button.
That’s it. The birthday is changed successfully.
Open Facebook app.
Hit the Hamburger icon (three vertical lines) at the top and then hit your profile (your name).
Under “Basic Info,” you can see your birthday. Hit the “Pencil” icon beside it.
Now, you can see a couple of drop-down lists (one for the month and another one for date) besides “Birthday” and a single one (for the year) besides “Birth Year.”
Tap the drop-down you prefer and make the changes as per your liking.
Scroll down until you see “Save” button. Hit it.
That’s all. Your birthday is changed successfully.
Note: If you want to hide birthday on Facebook, see this post.