If you want to hide your birthday on Facebook, then here’s how you can do that on PC and Android:
Sign into Facebook.
Hit the “Profile” (your name) which you can find between “Search Box” and “Home” at the top.
Between “Timeline” and “Friends,” you can see “About.” Hit it.
Under “About,” you can see “Contact and basic info.” Click on it.
Now, under “Basic Information,” you can see “Date of Birth,” “Year of Birth” and “Gender.”
Hover your mouse over “Date of Birth,” and you can see “Edit” link. Hit it.
Now, you can see two drop-down lists (one beside the date and month drop-down lists and another one beside year drop-down list).
Hit the drop-down list beside the date and month drop-down lists. Select “Only me.”
Hit the drop-down list beside year drop-down list. Select “Only me” option.
Hit “Save Changes” button.
That’s all. From now on, only you can see your birthday and no one else.
Open Facebook app.
Tap the Hamburger icon (three vertical lines) and then tap your profile (your name).
Find and tap “About.”
Under “Basic Info,” you can see your birthday. Hit the “Pencil” icon beside it.
Tap the drop-down list beside month and date drop-down lists and then select “Only me.”
Tap the drop-down list beside year drop-down list and then select “Only me.”
Hit the “Save” button at the bottom.
That’s all. From now, no one can see your birthday except yourself.