hijrikalendern

The Hijri calendar, also known as the Islamic calendar, is a lunar calendar used by Muslims to determine religious observances and historical dates. It consists of 12 lunar months in a year of 354 or 355 days, making it about 10 to 12 days shorter than the solar year. Months begin with the sighting of the crescent moon, though some communities also use calculations to predict new moons.

The months are Muharram, Safar, Rabi' al-awwal, Rabi' al-thani, Jumada al-awla, Jumada al-thani, Rajab, Sha'ban, Ramadan, Shawwal, Dhu al-Qi'dah, and Dhu al-Hijjah. The calendar is anchored to the Hijra, Prophet Muhammad's migration from Mecca to Medina in 622 CE, and year 1 AH marks that event.

Because the year is shorter than the solar year, the Hijri date shifts through the seasons relative to the Gregorian calendar. Islamic holidays such as Ramadan, Eid al-Fitr, and Eid al-Adha move about 10–11 days earlier each solar year.

In practice, the start of months is determined either by traditional moon sighting or by astronomical calculations, depending on local customs and authorities. Some countries publish official Hijri calendars for civil use, while others rely on regional or community-based announcements.