All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
We have already issued Fataawa 86137 and 84957 clarifying that it is not permissible for a person to celebrate his birthday, so please refer to them.
The ruling applies whether or not the celebration includes cutting a cake and whether or not this takes place on the very exact birthday, before it or after it. It is not reported that the Prophet or his companions have ever celebrated their birthdays.
Moreover, celebrating the birthday is an imitation of the non-Muslims.