Islamic calendar

The Islamic calendar, Muslim calendar or Hijri calendar^[1][2] is a lunar calendar consisting of 12 lunar months in a year of 354 or 355 days. Being a purely lunar calendar, it is not synchronized with the seasons. With an annual drift of 10 or 11 days, the seasonal relation repeats about every 33 Islamic years.

It is used to date events in many Muslim countries (concurrently with the Gregorian calendar), and used by Muslims everywhere to determine the proper days on which to observe the annual fast (see Ramadan), to attend Hajj, and to celebrate other Islamic holidays and festivals.

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),^[3] hence, Muslims typically call their calendar the Hijri calendar.

The current Islamic year is 1433 AH. In the Gregorian calender 1433 AH runs from approximately 26 November 2011 (evening) to 14 November 2012 (evening).

Months

Four of the twelve Hijri months are considered sacred, although there is disagreement over the designated months, such as between proponents for the sequences {7,11,12,1} vs. {12,1,2,3}^[4]. The twelve Hijri months are named as follows in Arabic:^[5]

1.    Muḥarram — المحرّم, "forbidden" — so called because it was unlawful (haram) to fight during this month.^[6] Muharram is the second most sacred Muslim month and includes the Day of Ashura.

2.   Ṣafar — صفر, "void" — supposedly named because pagan Arabs looted during this month and left the houses empty.

3.   Rabīʿ I (Rabīʿ al-Awwal) — ربيع الأوّل, "the first spring".

4.   Rabīʿ II (Rabīʿ ath-Thānī or Rabīʿ al-Ākhir) — ربيع الثاني or ربيع الآخر, "the second (or last) spring".

5.   Jumādā I (Jumādā al-Ūlā) — جمادى الأولى, "the first month of parched land". Often considered the pre-Islamic "summer".

6.   Jumādā II (Jumādā ath-Thāniya or Jumādā al-Ākhira) — جمادى الثانية or جمادى الآخرة, "the second (or last) month of parched land".

7.   Rajab — رجب, "respect" or "honor". This is another sacred month in which fighting was traditionally forbidden.

8.   Shaʿbān — شعبان, "scattered", marking the time of year when Arab tribes dispersed to find water.

9.   Ramaḍān — رمضان, "scorched". Ramadan is the most venerated month of the Hijri calendar during which Muslims must fast between dawn and sunset.

10.Shawwāl — شوّال, "raised", as she-camels begin to raise their tails during this time of the year, after giving birth.

11. Dhū al-Qiʿda — ذو القعدة, "the one of truce". Dhu al-Qi'da was another month during which war was banned.

12.Dhū al-Ḥijja — ذو الحجّة, "the one of pilgrimage", referring to the annual Muslim pilgrimage to Mecca, the Hajj.