Islamic New Year

The Islamic calendar, Muslim calendar or Hijri calendar (AH) is a lunar calendar consisting of 12 months in a year of 354 days. It is used to date events in many Muslim countries (concurrently with the Gregorian calendar). The first year was the Islamic year beginning in AD 622 during which the emigration of Muhammad from Mecca to Medina, known as the Hijra, occurred. Each numbered year is designated either "H" for Hijra or "AH" for the Latin Anno Hegirae ("in the year of the Hijra"); hence, Muslims typically call their calendar the Hijri calendar. Four of the twelve Hijri months are considered sacred: Rajab (7), and the three consecutive months of Dhū al-Qaʿdah (11), Dhu al-Ḥijjah (12) and Muḥarram (1). Because the lunar calendar lags behind the solar calendar by about ten days every year, months of the Islamic calendar fall in different parts of the Gregorian calendar each year. The cycle repeats every 33 years.

Each month of the Islamic calendar commences on the birth of the new lunar cycle. Traditionally this is based on actual witnessing of the crescent marking the end of the previous lunar cycle and hence the previous month thereby beginning the new month. Consequently, each month can have 29 or 30 days depending on the visibility of the moon, astronomical positioning of the earth and weather conditions. However, certain sects and groups, most notably Dawoodi Bohra Muslims and Shia Ismaili Muslims use a tabular Islamic calendar in which odd-numbered months have thirty days (and also the twelfth month in a leap year) and even months have 29.

The Hijri New Year, also known as Islamic New Year (Arabic: رأس السنة الهجرية‎ Raʼs al-Sanah al-Hijrīyah) is the day that marks the beginning of a new Islamic calendar year, and is the day on which the year count is incremented. The first day of the year is observed on the first day of Muharram, the first month in the Islamic calendar. All religious duties, such as prayer, fasting in the month of Ramadan, and pilgrimage, and the dates of significant events, such as celebration of holy nights and festivals, are calculated according to the lunar calendar.

While some Islamic organizations prefer determining the new month (and hence the new year) by local sightings of the moon, most Islamic institutions and countries, including Saudi Arabia, follow astronomical calculations to determine future dates of the Islamic calendar. There are various schema for calculating the tabular Islamic calendar (i.e. not based on observation), which results in differences of typically one or even two days between countries using such schema and those that use lunar sightings. For example, the The Umm al-Qura Calendar used in Saudi Arabia was reformed several times in recent years. The current scheme has been introduced in 1423 AH (15 March 2002).

A day in the Islamic calendar is defined as beginning at sunset. For example, 1 Muharram 1432 was defined to correspond to 7 or 8 December 2010 in official calendars (depending on the country). For an observation-based calendar, a sighting of the new moon at sunset of 6 December would mean that 1 Muharram lasted from the moment of sunset of 6 December to the moment of sunset of 7 December, while in places where the new moon was not sighted on 6 December, 1 Muharram would last from the moment of sunset of 7 December to the moment of sunset of 8 December.