10 August 610 to 19 April 571, a Sunday night in Rabi'I according to the fixed calendar proposed as Muhammad's date of birth by scholar Muhammad Sulaiman Al-Mansurpuri and astronomer Mahmud Pasha. This is 14,358 days. Taking the average length of an Islamic month as 29.53059 days, this equates to 486.21 months, which in the fixed calendar is 40 years, 6 months and 6 days. The 6 months and 12 days interval referred to above, on the other hand, is authentic and independent of this calculation. It is unaffected by whether or not the year is intercalated. It is the interval between the date of Muhammad's birth (after sunset on 11 Rabi'I) and the Shia date of first revelation (23 Ramadan). As further proof of its correctness, Muhammad died four days after his birthday, on 14 Rabi'I AH 11 (Monday, 8 June 632). Converting the Islamic date to Julian Given the day of the week, the date and the year any Muslim date in the intercalated calendar may be converted to Julian by utilising the known relationship between the intercalated calendar and the seasons. Under intercalation 12 Rabi'I (Muhammad's birth date) might fall in May or June. The exact date is Monday, 2 June 570. Under intercalation 23 Ramadan (the date of first revelation) might fall in November or December. The exact date is the night of Sunday to Monday, 13 to 14 December 610. Summary According to biographies of Muhammad, while on retreat in a mountain cave near Mecca (the cave of Hira), where Muhammad used to go and ponder upon the evil deeds of his community. Gabriel appears before him and commands him to "Read!". He responded, "But I cannot read!". Then the angel Gabriel embraced him tightly and then revealed to him the first lines of chapter 96 of the Qur'an, "Read: In the name of Allah Who created, (1) Created man from a clot. (2) Read: And Allah is the Most Generous, (3) Who taught by the pen, (4) Taught man that which he knew not.(5)" (Bukhari 4953). Before the revelation Muhammad was born and raised in Mecca. When he was nearly 40, he used to spend many hours alone in prayer and speculating over the aspects of creation. He was concerned with the ignorance of divine guidance (Jahiliyyah), social unrest, injustice, widespread discrimination (particularly against women), fighting among tribes and abuse of tribal authorities prevalent