Dhu al-Qa'dah, Dhu'l-Qadah, Thu-l-Qicda, or Dhu al-Qi'dah (Arabic: ذو القعدة, also transliterated Ḏū l-Qaʿdah, IPA: [ðʊlˈqɑʕda]) is the eleventh month in the Islamic calendar. It is one of the four sacred months in Islam during which warfare is prohibited, hence the name ‘Master of Truce’.
The Islamic calendar is a lunar calendar, and months begin when the first crescent of a new moon is sighted. Since the Islamic lunar calendar year is 11 to 12 days shorter than the solar year, Dhu al-Qa'dah migrates throughout the seasons. For example, some estimated start and end dates for Dhu al-Qa'dah are as follows:
1426 AH – First day: December 2, 2005; last day: December 31, 2005
1427 AH – First day: November 22, 2006; last day: December 21, 2006
1428 AH – First day: November 11, 2007; last day: December 10, 2007
1429 AH – First day: October 31, 2008; last day: November 29, 2008