It's not clear how this can help?
You asked about birth
day, Alex_197 replied about
date of birth, which might well be what you're actually looking for ie day, month
and year
abbreviated spelling of the phrase “birthday”
Use DOB - Date Of Birth in English
and so I included both, next to each other, to highlight the subtle difference between the two:
English:
Birthdate (including year) = DOB / D.O.B.
Birthday (happens every year) = bday / b'day
Except for loyalty schemes that send out birthday cards/vouchers/etc each year, most data collection is of birth
date, not birth
day, usually to confirm that a person is of a certain age eg over 13 for Facebook, over 18 to vote, under 30 for youth hostel, under 80 for travel insurance, etc.
An example of this is that passports show the
date of birth aka birthdate, not birthday: