Which of the following festivals is celebrated on Prophet Mohammed birthday?

The festival is called in Arabic 'Eid milad-un-Nabi'. However, it is to be emphasized that practicing this festival is not per religion; as the two festivals after end of Ramadan and that during hajj. Celebrating prophet Muhammad birthday, although not per religion, but it is not forbidden. It is considered as good occasion to remind Muslims with the prophet Muhammad teachings and morals and to renew the intention of following and adopting prophet Muhammad guides.