JOIN OUR MAILING LIST     facebook    twitter    skype

Guest Impressions

What is the Islamic Calendar ?

What is the Islamic Calendar ?


Although, the Islamic calendar was introduced in the Christian Era of 632 AD by the Messenger Muhammad (peace be upon him), the beginning of the Islamic era for the count of Islamic years was considered and discussed during 639 AD, the time of the 4th year of the Caliphate of Umar(R.A.) who declared that the most important event in establishing the roots of Islam in Madinah is Hijrah (Messenger's migration from Makkah), therefore let it become the epoch of the era which happened in 622 AD. The actual starting date for the Islamic Calendar was chosen (on the basis of purely lunar years, counting backwards) to be the first day of the first month (1st Muharram) of the year of the Hijrah. However, the era between 1st year to 10th year of the Hijrah was not following this Islamic Calendar; instead the prevailing practices of various kinds of intercalation was followed in Arabia at that time. Different tribes were following different intercalations, so there was no uniform calendar. Accordingly, first day of Muharram, 1 A.H. as practiced in Arabia corresponded either April 18 or May 18, 622 C.E. (Julian calendar). However, if one wants a theoretical starting date for Islamic calendar (on the basis of purely lunar months without intercalation, counting backwards) then the first day of the first month i.e. 1st Muharram, 1 A.H. corresponds to July 16, 622 C.E.

The Hijrah, which chronicles the migration of the Prophet Muhammad(sallallahu alaiyhi wassallam) from Makkah to Madinah in September 622 C.E., is the central historical event of early Islam. It led to the foundation of the first Muslim city-state, a turning point in Islamic and world history.

The earliest date of Islamic calendar for which a Julian calendar date is exactly known is 9th Dhul-Hijjah, 10 AH, which corresponds to March 6, 632 C.E. (Friday), when the Messenger Muhammad (peace be upon him) performed his last and farewell pilgrimage to Makkah.

The Islamic (Hijri) calendar (with dates that fall within the Muslim Era) is usually abbreviated A.H. in Western languages from the latinized Anno Hegirae or more commonly known as "After Hijrah.".

To Muslims, the Hijri calendar is not just a sentimental system of time reckoning and dating important religious events (e.g., Siyaam (fasting) and Hajj (pilgrimage to Makkah)). It has a much deeper religious and historical significance.

Muhammad Ilyes quotes Nadvi who wrote: ``It (the advent of the 15th century) is indeed, a unique occasion to ponder that the Islamic Era did not start with the victories of Islamic wars, nor with the birth or death of the Prophet (sallallahu alaiyhi wassallam), nor with the Revelation itself. It starts with Hijra, or the sacrifice for the cause of Truth and for the preservation of the Revelation. It was a divinely inspired selection. The Almighty wanted to teach man that struggle between Truth and Evil is eternal. The Islamic year reminds Muslims every year not of the pomp and glory of Islam but of its sacrifice and prepares them to do the same.''

From a historical angle, Ilyes quotes Samiullah who writes: "All the events of Islamic history, especially those which took place during the life of the Prophet(sallallahu alaiyhi wassallam) and afterwards are quoted in the Hijra calendar era. But our calculations in the Gregorian calendar keep us away from those events and happenings, which are pregnant of admonitory lessons and guiding instructions. ...And this chronological study is possible only by adopting the Hijri calendar to indicate the year and the lunar month in line with our cherished traditions.''


The Islamic calendar is based on lunar months, which begin when a thin new crescent Moon is actually sighted in the western sky after sunset within a day or so after the New Moon. Hence, the month is either 29 days or 30 days. There are 12 months in an Islamic year, which is either 354 days long or 355 days long, compared to (Gregorian) civil calendar year of 365 or 366 days. Since the Islamic Lunar year has 12 lunar months, it is on an average, 11 days shorter than the (Gregorian) civil year, the Islamic year shifts earlier in each civil year by about 11 days.

The Islamic (Hijri) year consists of twelve (purely lunar) months.

They are: (1) Muharram (2) Safar (3) Rabi ul-awal (4) Rabi ul-Thaany (5) Jumaada al-awal (6) Jumaada al-Thaani (7) Rajab (8) Sha`baan (9) Ramadhaan (10) SHawwal (11) Thul -Qa'dah (12) Thul-Hijjah

It is considered a divine command to use a (Hijra) calendar with 12 (purely) lunar months without intercalation [Ilyes84], as evident from the following verses of the Holy Qur`an: "They ask thee the New Moons. Say: They are but signs To mark fixed periods of time. In (the affairs of) men And for Pilgrimage." (Qur'an II:189)

" The number of months In the sight of Allah Is twelve (in a year). So ordained by Him, The day He created The heavens and the earth; Of them four are sacred; that is the straight usage, So wrong not yourselves therein, and fight the Pagans." ( Qur'an IX: 36)

Since the Islamic calendar is purely lunar, as apposed to solar or luni-solar, the Muslim (Hijri) year is shorter than the Gregorian year by about 11 days,and months in the Islamic (Hijri) year are not related to seasons, which are fundamentally related to the solar cycle. This means that important Muslim festivals, which always fall in the same Hijri month, may occur in different seasons. For example, the Hajj and Ramdhaan can take place in the summer as well as the winter. It is only over a 33 year cycle that lunar months take a complete turn and fall during the same season.

For religious reasons, the beginning of a Hijri month is marked not by the start of a new moon, but by a physical (i.e. an actual human) sighting of the crescent moon at a given locale.

However, determining the VISIBILITY of the crescent may vary from place to place; rather it is dependent upon several factors, mostly optical in nature. This makes it difficult to produce (in advance) Islamic calendars that are reliable (in the sense that they are consistent with actual crescent visibility).

Efforts for obtaining an astronomical criterion for predicting the time of first lunar visibility go back the the Babylonian era, with significant improvements and work done later by Muslim and other scientists. These efforts have resulted in the development in a number of criteria for predicting first possible sighting of a crescent.

However, there remains a measure of uncertainty associated with all criteria developed thus far. Moreover, there has been little work in the area of estimating crescent visibility on global (as apposed to local) scale. Until this happens, no Hijri calendar software can be 100% reliable, and actual crescent sighting remains essential especially for fixing important dates such as the beginning of Ramadhaan and the two eids.

The slight differences in printed Islamic calendars, worldwide, can therefore be traced to two primary factors: (1) the absence of a global criterion for first visibility; and (2) the use of different visibility criterion (or method of calculation). Weather conditions and differences in the observer's location also explain why there are sometimes differences in the observances of Islamic dates, worldwide.

By Waleed Muhanna -Tuesday 13 Jumaadul Thaany 1413 A.H. (December 8, 1992)

Alislaah publications

Leave a comment

Anti-spam: complete the taskJoomla CAPTCHA

GET CONNECTED WITH US       facebook       twitter      skype