The Islamic Calendar

Its History & Rationale

Abstract from SKH article.

  1. The Islamic calendar, which is based purely on lunar cycles, was introduced in 638CE by Umar bin al Khattab, who was a close Companion of the Prophet Muhammad (peace be upon him) and the second Caliph of Islam. Umar did it in an attempt to rationalize the various, at times conflicting, dating systems used during his time.

  2. He consulted his advisers on the starting date of the new Muslim chronology. It was finally agreed that the most appropriate reference point for the Islamic calendar was of Hijra, which chronicles the divinely ordained migration of the Holy Prophet and his Companions from Makkah to Madinah on September 20, 622CE. For this reason, the Islamic calendar is known as the Hijra calendar.

  3. The actual starting date for the Hijra calendar was chosen (on the basis of purely lunar years, counting backwards) to be the first day of the first month (1 Muharram) of the year of Hijrah. Thus 1 Muharram, 1AH, corresponds to July 15, 622CE. A Hijra year is usually abbreviated AH in Western languages from the Latinised Anno Hegirae.

  4. Hijrah 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. To Muslims, the Hijra calendar is not just a sentimental system of time reckoning and dating important religious events, e.g. Siyaam (fasting) and Haj. It has a much deeper religious and historical significance.

  5. It is a unique aspect of the Islamic Era that it did not start with the victories of Islamic wars, or with the birth or death of the Holy Prophet, or the Revelation of the Holy Quran. It starts with Hijra or the sacrifice for the cause of Truth and for the preservation off the Revelation. It was divinely inspired selection. Allah 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.

  6. The Islamic year consists of twelve lunar months. They are Muharram, Safar, Rabee' al-Awwal, Rabee' ath-Thaanee / al-Aakhir, Jumaada al-Oolaa, Jumaada ath-Thaaniyah / al-Aakhirah, Rajab, Sha'baan, Ramadhan, Shawwaal, Dhul-Qi'dah and Dhul-Hijjah.

  7. The most important dates in an Islamic year are: 1 Muharram (first day of the year), 27 Rajab (Isra and Mairaj), 1 Ramadhan (first day of fasting), 17 Ramadhan (Battle of Badr), last 10 days of Ramadhan (which include Lailatul Qadar when the Holy Quran was revealed), 1 Shawwal (Eid Al-Fitr) & 10 Dhul-Hijjah (Eid ul Adha).

  8. In establishing the new Islamic calendar, the Caliph Omar relied on several passages of the Holy Quran, including the following ones:

    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 all together as they fight you all together. But know that Allah is with those who restrain themselves. Verily the transposing (of a prohibited month) is an addition to Unbelief: the unbelievers are led to wrong thereby: for they make it lawful one year, and forbidden another year, in order to adjust the number of months forbidden by Allah and make such forbidden ones lawful

    (Al-Taubah 9V. 36-37)

    It is He who made the sun to be shining glory and the moon to be alight (of beauty), and measured out stages for her; that you might know the number of years and the count (of time)."

    (Al-Yunus 10V. 5)

  9. As the Islamic world runs on lunar time, the calendar slips back 11 days for every year, and special days important in the life of every Muslim travel all around the year. Thus, the months have no permanent relation to the seasons. For instance, the fasting month of Ramadhan (the ninth month of the Islamic calendar) may occur in winter, summer, spring or autumn, making a complete cycle every 33 Gregorian years.


Dawaah (Invocation) Dawaah means to call, to invite. A Muslim who has received the message of Allah must do his utmost to communicate this message to other human beings. This Dawaah work in its nature is a prophetic task. The more one follows the way of the Prophet in the performance of this task, the greater the reward one will receive for it.

"Invite (mankind, O Muhammad(PBUH) to the Way of your Lord (i.e. Islam) with wisdom (i.e. with the Divine Revelation and the Quran) and fair preaching, and argue with them in a way that is better. Truly, your Lord knows best who has gone astray from His Path, and He is the Best Aware of those who are guided."

(Al-Nahl 16V. 125)

Please pray to Allah (swt) for the success of the Islamic perspective and presentation in this Dawaah article.

This page last updated 10/11/2009 12:39 p.m.