Muhammad's first revelation was an event described in Islamic tradition as taking place in 610 AC, during which the Islamic prophet, Muhammad was visited by the angel Jibrīl, known as Gabriel in English, who revealed to him the beginnings of what would later become the Qur'an.
The event took place in a cave called Hira, located on the mountain Jabal an-Nour, near Mecca. As for the exact date of this event, it has been calculated to be on Friday, the 17th of Ramadan at night, i.e. August 6, 610 C.E. - when Muhammad was 40 lunar years, 6 months and 12 days of age, i.e. 39 Gregorian calendar years, 3 months and 22 days.[1] [2] 6 August 610 (Julian) was actually a Thursday. The proleptic Gregorian calendar is two days ahead in the sixth century and three days ahead in the seventh.