The Islamic calendar is based on lunar year. A lunar year gener-ally follows the monthly cycles of the moon. A lunar month is
determined by the period required for the moon to complete a full circle around the Earth, which takes about 29½ days. Twelve months of 29½ days each combine to make 354 days, the number of days in a lunar year. Based on these calculations, the Islamic lunar calendar is about eleven days shorter than the solar-based Gregorian calendar, which counts 365 days (366 in a leap year) because it is based on the movement of the Earth around the sun.
This eleven-day deficit causes each lunar month to move with the seasons, which are based on solar cycles. This means that important Muslim festivals, which always fall in the same month on the Islamic lunar calendar, may occur in different seasons based on the solar cycle. For instance, the fasting month of Ramadan could come in either winter or summer. Because of the eleven-day deficit of the lunar year, any given date on the Islamic calendar moves eleven days backward each year when measured on the solar-based Gregorian calendar. So, it takes about thirty-three years for a particular event on the Islamic calendar to complete its variations within seasons and occur again at approximately the same time on the solar calendar. For example, if the month of Ramadan occurred in October 2004 (on the Gregorian calendar), ten years later it will happen in July, and thirty-three years later it will be in October once again.
The Islamic Hijri calendar was introduced to the Muslim community in Medina in 638, during the caliphate of Umar ibn al-Khattab, the second caliph and a close companion of the prophet Muhammad. The dates of Islamic Hijri calendar in Western languages are usually abbreviated as “A.H.” from the Latinized “Anno Hegirae.” This term meant “Year of the Hegira,”
with the word Hegira referring to Muhammad’s flight from Mecca to Medina.
The Beginning of the Islamic Hijri Calendar
Interestingly, the Islamic calendar is not based on the birth of the Prophet, the major conquests of the Islamic Army, or even the day of the Prophet’s first revelation. Instead, it starts on the day
that the prophet Muhammad emigrated from Mecca to Medina, a major historical event and turning point in Islamic history that led to the formation of the first genuine Islamic community and city-state in Medina. The calendar, therefore, is based on the day that Muhammad decided to bring a new beginning to his mission by moving to a more sympathetic city, hoping to establish the community he envisioned based on God’s guidance in the Qur’an and just principles.
As a result of its starting point, the calendar is called Hijri, a term derived from the word hijrah, meaning “emigration.”
The Islamic Hijri year starts at the first day of the month of Muharram (the first month of the year), which is roughly the equivalent of July 16, 622. The Muslim New Year 1425 started around February 22, 2004. Because the Islamic lunar calendar is eleven days shorter, it will eventually catch up to the Gregorian calendar. According to calculations done by specialists in the field, the fifth month of the year 20,874 on the Hijri calendar will also be the fifth month of the year 20,874 on the Gregorian calendar.12
Months of the Islamic Calendar
The Islamic months begin at the first sight of the new moon.
Since the moon is seen at different times in different Muslim regions, there is no uniform beginning for months and years throughout the entire Islamic world. Most Muslims use the sighting of the new moon in their own location to determine the beginning of the new month. However, some Muslims consider the sighting of the new moon in Mecca, Saudi Arabia, the official beginning of each month, since Mecca is Islam’s holiest city.
The correct sighting is particularly important for performing religious rituals, such as the beginning and ending of fasting days during the month of Ramadan. The Qur’an refers to the significance of the phases of the moon for conducting religious rituals: “They ask you (Muhammad) of the new moons. Say:
they are but signs to mark fixed periods of time in (the affairs of) mankind and for the pilgrimage . . .” (Q: 2:189). With regard to
months of the year, the Qur’an states: “The number of months in the sight of God is twelve, so ordained by Him the day He created the heavens and the earth; of them four are sacred . . .”
(Q. 9:36). For orthodox Muslims, a new month is considered to have begun only when it is announced by religious authorities who have seen the thin crescent moon with their own eyes.
This makes marking the new month difficult when there is very low visibility.
The Islamic Hijri calendar contains twelve months that alter-nate between 29 and 30 days; the last month has 30 days only during leap years. A thirtieth day is added to the last month in eleven years out of every thirty-year cycle. Those years are the second, fifth, seventh, tenth, thirteenth, sixteenth, eighteenth, twenty-first, twenty-fourth, twenty-sixth, and twenty-ninth. The months of Islamic calendars are:
MONTH(DAYS)
1 Muharram (30) 2 Safar (29)
3 Rabi’-ul awwal I (30) 4 Rabi’-ul thani II (29) 5 Jumada-ul awwal I (30) 6 Jumada-ul thani II (29) 7 Rajab (30)
8 Sha’ban (29) 9 Ramadan (30) 10 Shawwal (29) 11 Dhul Qa’da (30)
12 Dhul Hijjah (29; 30 days in leap years)