Conversion of Hijri years 1343 to 1500 to the Gregorian calendar, with first days of al-Muharram (brown), Ramadan (grey) and Shawwal (black) bolded, and Eid al-Adha dotted – in the SVG file, hover over a spot to show its dates and a line to show the month
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, Muharram migrates throughout the solar years. The estimated start and end dates for Muharram are as follows (based on the Umm al-Qura calendar of Saudi Arabia)