Hijri era
The Hijri era is the calendar era used to record dates in the Islamic world. Its epoch is the year in which Muhammad and his followers migrated from Mecca to Yathrib, in. This event, known as the Hijrah, is commemorated in Islam for its role in the founding of the first Muslim community. Time in this era is measured by two principal calendars: the lunar Hijri calendar which counts lunar years since the Hijrah and which is used by most Muslims around the world; and the solar Hijri calendar which counts solar years since the Hijrah and which is used in Iran.
In the West, dates in the lunar Hijri calendar are denoted as AH or Hijri year in the style of the Christian/Common and Jewish eras and can similarly be placed before or after the date. In predominantly Muslim countries, it is also commonly abbreviated H from its Arabic abbreviation . Years prior to AH 1 are reckoned in English as BH, which follows the date. Dates in the solar Hijri calendar are denoted as SH. The current year according to the lunar Hijri calendar is ; according to the solar Hijri calendar the current year is. The difference in numbering arises because a lunar year is about eleven days shorter than a solar year.
A year in a lunar calendar consists of twelve lunar months and has only 354 or 355 days in its year. Consequently, its New Year's Day occurs ten days earlier each year relative to the Gregorian calendar. The year CE corresponds to the Islamic years AH - ; AH1447 corresponds to 20252026 in the Common Era. The solar Hijri calendar corresponds closely with the Gregorian calendar but its year begins on the March equinox rather than on 1January.
Definition
The Hijri era is calculated according to the Islamic lunar calendar, whose epoch is the year of Muhammad's Hijrah, and begins on the first day of the month of Muharram.The date of the Hijrah itself did not form the Islamic New Year. Instead, the system continues the earlier ordering of the months, with the Hijrah occurring around the 8th day of Rabi al-Awwal, 66 days into the first year.
Shia view
Unlike Sunnis, Twelver Shias start the Hijri year with the month of the Hijra, Rabi' al-Awwal, rejecting that Muharram is the start of a new year. As a result of this, the dates of some events are described differently by one year. For example, Shias state that the Muharram-transpiring battle of Karbala occurred 60 years after the Hijra, while Sunnis state it to have occurred 61 years after.In Shia Islam, the calendar year is entirely determined by solar observation or calculation. Each year begins on the northward equinox.
History
Predecessors
By the age of Muhammad, there was already an Arabian lunar calendar, with named months. Likewise, the years of its calendar used conventional names rather than numbers: for example, the year of the birth of Muhammad and of Ammar ibn Yasir was known as the "Year of the Elephant". The first year of the Hijra was named the "Permission to Travel" in this calendar.Establishment
17 years after the Hijra, a complaint from Abu Musa Ashaari prompted the caliph Umar to abolish the practice of named years and to establish a new calendar era. Umar chose as epoch for the new Muslim calendar the hijrah, the emigration of Muhammad and 70 Muslims from Mecca to Medina. Tradition credits Othman with the successful proposal, simply continuing the order of the months that had already been established by Muhammad, beginning with Muharram, as there was no set order of months during the pre-Islamic era. Adoption of this calendar was then enforced by Umar.Formula
Different approximate conversion formulas between the Gregorian and the Islamic lunar calendars are possible:AH = 1.030684 ×
CE = 0.970229 × AH + 621.5643
or
AH = ×
CE = AH × + 622
Given that the Islamic New Year does not begin January 1 and that a linar Hijri calendar year is about 11 days shorter than a Gregorian calendar year, there is no direct correspondence between years of the two eras. A given Hijri year will usually fall in two successive Gregorian years. A CE year will always overlap two or occasionally three successive Hijri years. For example, the year 2008 CE maps to the last week of AH 1428, all of 1429, and the first few days of 1430. Similarly, the year 1976 CE corresponded with the last few days of AH 1395, all of 1396, and the first week of 1397.
The solar Hijri calendar year is almost exactly the same length as a Gregorian calendar year and, although it always begins at the March equinox, date conversion between the systems is trivial.