For central Arabia, especially Mecca, there is a lack of epigraphical evidence but details are found in the writings of … See more

Traditionally, the Islamic day begins at sunset and ends at the next sunset. Each Islamic day thus begins at nightfall and ends at the end of daylight.
The days in the seven-day week are, with the excepti… See more

Each month of the Islamic calendar commences on the birth of the new lunar cycle. Traditionally, this is based on actual observation of the moon's crescent (hilal) marking the end of the previous lunar cycle and hence … See more

The mean duration of a tropical year is 365.24219 days, while the long-term average duration of a synodic month is 29.530587981 days. Thus the average lunar year (twelve new moons) is 10.87513 days shorte… See more

In pre-Islamic Arabia, it was customary to identify a year after a major event which took place in it. Thus, according to Islamic tradition, Abraha, governor of Yemen, then a province of the Christian Kingdom of Aksum… See more

Due to the Islamic calendar's reliance on certain variable methods of observation to determine its month-start-dates, these dates sometimes vary slightly from the month-start-dates of the astronomical lunar calendar, w… See more

If the Islamic calendar were prepared using astronomical calculations, Muslims throughout the Muslim world could use it to meet all their needs, the way they use the Gregorian calendar today. But, there are divergent vi… See more