To see birthdays on Facebook on Mobile devices, whether it’s Android or iPhone, follow these simple steps:
1. Open the Facebook app on your phone.
2. Next, click on the Search option at the top of the screen.
3. Enter Birthdays in the search bar.
4. Then, select the first opinion that appears, i.e., Birthdays from the results shown.
5. Here, you find all the upcoming birthdays of your Facebook friends.
To read more: https://allinsider.net/how-to-find-birthdays-on-facebook/