Day of Ashura
Arbaʽein always falls 40 days after the Day of Ashura. The Day of Ashura, in turn, falls nine days after the first day of Muḥarram. Hence, Arbaʽein falls 49 days after the first day of Muḥarram. This date is shown for a selection of years, according to the Umm al-Qura Calendar of Saudi Arabia, in the table below: