Hajj
The pilgrimage occurs from the 8th to 12th (or in some cases 13th) of Dhu al-Hijjah, the last month of the Islamic calendar. Because the Islamic calendar is lunar and the Islamic year is about eleven days shorter than the Gregorian year, the Gregorian date of Hajj changes from year to year. Ihram is the name given to the special spiritual state in which pilgrims wear two white sheets of seamless cloth and abstain from certain actions.