The Islamic calendar (or Hijri calendar) is a lunar calendar. It contains 12 months that are based on the motion of the moon, and because 12 lunar months is 12 x 29.53=354.36 days, the Islamic calendar is consistently shorter (11 Days) than a solar year, and therefore it shifts with respect to the Gregorian calendar.
It is used to date events in many Muslim countries (concurrently with the Gregorian calendar), and used by Muslims everywhere to determine the proper day on which to celebrate Islamic holy days and festivals. The first year was the year during which the migration of the Prophet 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).
Being a purely lunar calendar, it is not synchronized with the seasons. With an annual drift of 11 or 12 days, the seasonal relation repeats about every 33 Islamic years.
What does the Quran say about measurement of time?
- [Quran – 9.36] Surely the number of months with Allah is twelve months in Allah’s ordinance since the day when He created the heavens and the earth..
- [Quran – 31:29] Seest thou not that Allah merges Night into Day and he merges Day into Night; that He has subjected the sun, and the moon (to his Law), each running its course for a term appointed; and that Allah is well-acquainted with all that ye do?
- [Quran – 103: 1..3] By (the Token of) Time (through the ages),- Verily Man is in loss, – Except such as have Faith, and do righteous deeds, and (join together) in the mutual teaching of Truth, and of Patience and Constancy.
How is an Islamic month determined?
Each month starts when the lunar crescent is first seen after a new moon. Although new moons may be calculated quite precisely, the actual visibility of the crescent is difficult to predict. It depends on factors such as weather, the optical properties of the atmosphere, and the location of the observer. Therefore in some cases it may be difficult to give accurate information in advance about when a new month will start.
Furthermore, in some areas Muslims depend on a local sighting of the moon, whereas in other areas a universal sighting is accepted. (i.e. if a new crescent is seen anywhere in the world it is accepted for communities the world over). Both are valid Islamic practices, but they may lead to different starting days for the months.
Moon Sighting Websites & Additional Information
- Moonsighting.comprovides moon visibility curves for the current year and next year.
- The Islamic Crescents’ Observation Project (ICOP) – provides moon sighting data from around the world.
- U.S. Naval Observatory– lists new moon birth times for the whole year. NB – the crescent moon will not be visible until at least 15 hours after the birth of the new moon.
- The Visibility of the Crescent Moon – an explanation of Moon visibility calculations from USNO
- Royal Observatory Greenwich – provides various articles on new moon and Islamic calendar.
- Prayer Times – get your local prayer times. A Gregorian/Hijri date converter is also provided.
The Islamic months are named as follows in Arabic:
Muḥarram — المحرّم, “forbidden” — so called because it was unlawful to fight during this month. Muharram is the second most sacred Muslim month and includes the Day of Ashura.
Ṣafar — صفر, “void” — supposedly named because pagan Arabs looted during this month and left the houses empty.
Rabīʿ I (Rabīʿ al-Awwal) — ربيع الأوّل, “the first Spring”.
Rabīʿ II (Rabīʿ ath-Thānī) or (Rabīʿ al-Ākhir) — ربيع الثاني or ربيع الآخر, “the second (or last) Spring”.
Jumādā I (Jumādā al-Ūlā) — جمادى الأولى, “the first month of parched land”.
Jumādā II (Jumādā ath-Thāniya or Jumādā al-Ākhira) — جمادى الآخرة , جمادى الثانية, “the second (or last) month of parched land”.
Rajab — رجب, “respect” or “honor”. Rajab is another of the sacred months in which fighting was traditionally forbidden.
Shaʿbān — شعبان, “scattered”, marking the time of year when Arab tribes dispersed to find water.
Ramaḍān — رمضان, “scorched”. Ramadan is the most venerated month of the Hijri calendar, during which Muslims fast between dawn and sunset.
Shawwāl — شوّال, “raised”, as she-camels begin to raise their tails during this time of the year, after giving birth.
Dhū al-Qaʿda — ذو القعدة, “the one of truce”. Dhu al-Qa’da was another month during which war was banned.
Dhū al-Ḥijja — ذو الحجّة, “the one of pilgrimage”, referring to the annual Muslim pilgrimage to Mecca, the Hajj.