About Dhu al-Qadah
Dhu al-Qadah (ذُو ٱلْقَعْدَة) is the eleventh month of the Hijri calendar. Its name means “The one of truce.” The eleventh month and a sacred month, traditionally a time of truce ahead of the pilgrimage season. It is one of the four sacred months (Dhu al-Qadah, Dhu al-Hijjah, Muharram, and Rajab), in which fighting was traditionally prohibited.
Like every Hijri month it has 29 or 30 days, determined in the Umm al-Qura calendar by the official tables and in the tabular calendar by a fixed arithmetic rule. Because the lunar month depends on the sighting of the new crescent, the exact first day can differ by a day from the calculated date.