Jakarta (Indonesia Window) - Abu Musa Al-Ash'ari, the governor of Basrah (Iraq) at the time of Umar bin Al-Khattab (radhiallahu 'anhu) caliphate, once complained to him about the inconsistency of the dates written on the correspondences he received.

Abu Musa Al-Ash'ari then sent a letter to the second caliph, asking him to develop a new way to calculate dates.

Umar (radhiallahu 'anhu) then discussed the issue with his advisers.

Some suggested that the Prophet's ﷺ birth date should mark the initial of the new calendar, while others suggested the date of his death.

However, the majority agreed that the Islamic calendar should refer to the Prophet's migration from Makkah to Madinah, or so-called hijra, as it is the central event of early Islam, the turning point in Islamic history that led to the foundation of the first Muslim state.

Caliph Umar (radhiallahu 'anhu) then consulted with Uthman bin Affan and Ali bin Abi Talib (radhiallahu' anhuma), and they agreed.

The Islamic calendar was finally determined with the first month of Muharram, and ends with the month of Dhul Hijjah. Therefore, in the AD or solar calendar, the Prophet ﷺ migration event occurred in 622.

The determination of the Hijri calendar occurred 17 years after the Prophet ﷺ passed away, or around the third or fourth year of succession of Umar (radhiallahu 'anhu).

Moon phase

Unlike the Gregorian or solar calendar, which is determined based on the circulation of the Earth to the sun (so that the beginning and end of each month follows the seasons), the Hijri calendar is based on the moon's orbit to the Earth.

The invisibility of the moon marks the end of a month, and conversely, the appearance of a new moon is the beginning of the next month, making the Hijri calendar unrelated to the seasons.

One year in the Hijri calendar consists of 354 or 355 days because it has fewer days (usually 11 days shorter) than the Gregorian year which has 365 days. This is because the duration of one month in the Islamic calendar amounts to 29 or 30 days, and never 31 days.

Therefore, observation of the moon should be made on the 29th of each month to determine whether or not this month continues until the 30th or has entered a new month.

In the Hijri calendar, the sunset is a sign of a new day or date, not 00.01 o’clock as on the Gregorian calendar.

Worldwide only Turkey, Saudi Arabia, Kuwait, the Islamic Society of North America, Iran and Afghanistan use the Hijri calendar.

Some other Muslims will refer to the Hijri calendar only when entering the month of Ramadan, the celebration of Eid al-Fitr and Eid al-Adha, or when commemorating historical events in Islam, such as Isra Mi'raj, the birth of the Prophet ﷺ, and the new of year.

In fact, the Hijri calendar is mentioned in the Quran in Chapter At-Taubah (9) verse 36, with a translation, “Verily the number of months with Allah is twelve months in the Book of Allah, (since) the day He created the heavens and the earth, four of them are sacred. That is the established religion. So be you not unjust unto your selves during them. And fight polytheists totally even as they fight you totally, and know that Allah is with the pious ones”.

Each month in the Hijri calendar has a special meaning, and the four haram (forbidden) months mentioned in the Quran are Muharram, Dzulqaidah, Dhul Hijjah and Rajab.

1. The first month of the Hijri year, given its name (forbidden) because of fighting is forbidden during it.
2. The second month in the Hijri year, apparently named Safar (zero or empty) because Arabs used to loot the houses of their enemies after defeating them in battle, leaving nothing (zero) behind.
3. Rabi Al Awwal and Rabi Al Akhar. The third and four months in the Hijri year. These two months coincided with the spring, as well as a period when those victorious in war could enjoy their new possessions, seized in the previous month of Safar.
4. Jumada Al Ula and Jumada Al Akhira. The fifth and six months in the Hijri year, coinciding with the winter season and water freezing.
5. The seventh month in the Hijri year, meaning respect and honor.
6. Sha’aban. The eighth month in the Hijri year. Apparently named for the crossings or journeys the Arabs undertook in search of water whilst going to war. Sha’aban follows a month of abstinence from violence during the previous month of Rajab.
7. The ninth month in the Hijri year. It is named for the high temperatures caused by the summer sun and, it is the traditional fasting month for Muslims.
8. The 10th month in the Hijri year. It is named due to being the seasonal birthing season for camels, which would normally raise their tails in this season.
9. Dhul Qa’da. The 11th month in the Hijri year. It is named after the Arabic word for ‘sitting’. It is a holy month where Muslims must ‘sit out’ or abstain from war (although it is permissible to defend yourself if attacked).
10. Dhul Hijjah. The last month of Hijri Year, during which the Hajj pilgrimage is implemented.

Welcome 1442 Hijri!

Reporting by Indonesia Window