Question: When is Hajj 2012? Hajj, the pilgrimage to Mecca, is one of the greatest religious observances in Islam. What are the dates for Hajj in 2012? Answer: Hajj is expected to fall between October 24-29, 2012. Note: The exact dates of Islamic holidays cannot be determined in advance, due to the nature of the Islamic lunar calendar. Estimates are based on expected visibility of the hilal (waxing crescent moon following a new moon) and may vary according to location.