What is Islamic calendar

The Islamic schedule (Arabic: ٱلتَّقْوِيم ٱلْهِجْرِيّ‎ at-taqwīm al-hijrīy), otherwise called the Hijri, Lunar Hijri, Muslim or Arabic schedule, is a lunar schedule comprising of 12 lunar months in a time of 354 or 355 days. It is utilized to decide the best possible long periods of Islamic occasions and customs, for example, the yearly time of fasting and the best possible time for the Hajj. The common schedule of practically all nations where the religion is prevalently Muslim is the Gregorian schedule, with Syriac month-names utilized in the Levant and Mesopotamia (Iraq, Syria, Jordan, Lebanon and Palestine). Outstanding exemptions to this standard are Iran and Afghanistan, which utilize the Solar Hijri schedule. Rents, compensation and comparable standard responsibilities are commonly paid by the common calendar.[citation needed] 

Also, Check out-What Does A.H. Stand for in Islam?

The Islamic schedule utilizes the Hijri time whose age was set up as the Islamic New Year of 622 AD/CE. During that year, Muhammad and his supporters relocated from Mecca to Medina and set up the main Muslim people group (ummah), an occasion recognized as the Hijra. In the West, dates in this time are typically indicated AH (Latin: Anno Hegirae, "in the time of the Hijra") in corresponding with the Christian (AD), Common (CE) and Jewish times (AM). In Muslim nations, it is additionally in some cases signified as H from its Arabic structure (سَنَة هِجْرِيَّة, shortened ھ). In English, years preceding the Hijra are figured as BH ("Before the Hijra").

The current Islamic year is 1441 AH. In the Gregorian schedule, 1441 AH runs from roughly 31 August 2019 to 20 August 2020.

Also See: Orthodox Vs. Catholic Calendar

Pre-Islamic calendar

For focal Arabia, particularly Mecca, there is an absence of epigraphical proof however subtleties are found in the compositions of Muslim creators of the Abbasid period. Engravings of the old South Arabian schedules uncover the utilization of various nearby schedules. Probably a portion of these South Arabian schedules followed the lunisolar framework. Both al-Biruni and al-Mas'udi propose that the old Arabs utilized that month names as the Muslims, however they additionally record other month names utilized by the pre-Islamic Arabs.

The Islamic convention is consistent in expressing that Arabs of Tihamah, Hejaz, and Najd recognized two kinds of months, allowed (ḥalāl) and taboo (ḥarām) months. The illegal months were four months during which battling is prohibited, recorded as Rajab and the three months around the journey season, Dhu al-Qa'dah, Dhu al-Hijjah, and Muharram. A comparable if not indistinguishable idea to the prohibited months is additionally validated by Procopius, where he depicts a cease-fire that the Eastern Arabs of the Lakhmid al-Mundhir regarded for two months in the mid year solstice of 541 AD/CE. However, Muslim history specialists don't connect these months to a specific season. The Qur'an joins the four illegal months with Nasī', a word that actually signifies "postponement". According to Muslim custom, the choice of deferment was directed by the clan of Kinanah, by a man known as the al-Qalammas of Kinanah and his relatives (pl. qalāmisa).

Hijri to Gregorian Date Converter https://islamfly.com/en/hijri-to-gregorian-converter/

ALSO READ: The Gregorian Calendar

Various understandings of the idea of Nasī' have been proposed. Some researchers, both Muslim and Western, keep up that the pre-Islamic schedule utilized in focal Arabia was a simply lunar schedule like the cutting edge Islamic schedule. As per this view, Nasī' is identified with the pre-Islamic acts of the Meccan Arabs, where they would change the circulation of the prohibited a very long time inside a given year without inferring a schedule control. This translation is upheld by Arab history specialists and etymologists, as Ibn Hisham, Ibn Manzur, and the corpus of Qur'anic exegesis.

This is confirmed by an early Sabaic engraving, where a strict ceremonial was "delayed" (ns''w) because of war. As per the setting of this engraving, the action word ns'' has nothing to do with intercalation, however just with moving strict occasions inside the schedule itself. The similitude between the strict idea of this antiquated engraving and the Qur'an recommends that non-calendaring deferment is additionally the Qur'anic importance of Nasī'. The Encyclopedia of Islam finishes up "The Arabic arrangement of [Nasī'] can just have been proposed to move the Hajj and the fairs related with it in the region of Mecca to an appropriate period of the year. It was not expected to set up a fixed schedule to be by and large observed." The expression "fixed schedule" is commonly comprehended to allude to the non-intercalated schedule. 

Others agree that it was initially a lunar schedule, however propose that around 200 years before the Hijra it was changed into a lunisolar schedule containing an intercalary month added every now and then to keep the journey inside the period of the year when product was generally plentiful. This translation was first proposed by the medieval Muslim stargazer and space expert Abu Ma'shar al-Balkhi, and later by al-Biruni, al-Mas'udi, and some western scholars. This understanding considers Nasī' to be an equivalent word to the Arabic word for "intercalation" (kabīsa). The Arabs, as indicated by one clarification referenced by Abu Ma'shar, educated of this sort of intercalation from the Jews. The Jewish Nasi was the official who chose when to intercalate the Jewish calendar. Some sources state that the Arabs followed the Jewish practice and intercalated seven months more than nineteen years, or, in all likelihood that they intercalated nine months more than 24 years; there is, in any case, no agreement among researchers on this issue. 

Delay (Nasī') of one custom in a specific situation doesn't suggest change of the grouping of months, and researchers concur this didn't occur. Al-Biruni likewise says this didn't happen, and the celebrations were kept inside their season by intercalation consistently or third year of a month between Dhu al-Hijjah and Muharram. He likewise says that, regarding the fixed schedule that was not presented until 10 AH (632 AD/CE), the principal intercalation was, for instance, of a month between Dhu al-Hijjah and Muharram, the second of a month among Muharram and Safar, the third of a month among Safar and Rabi'I, thus on. The intercalations were masterminded so that there were seven of them like clockwork. The notification of intercalation was given at the journey, the following month would be Nasī' and Muharram would follow. In the event that, then again, the names identify with the intercalated as opposed to the fixed schedule, the subsequent intercalation may be, for instance, of a month among Muharram and Safar taking into consideration the primary intercalation, and the third intercalation of a month among Safar and Rabi'I taking into account the two going before intercalations, etc. The ideal opportunity for the intercalation to move from the earliest starting point of the year as far as possible (twelve intercalations) is the time it takes the fixed schedule to rotate once through the seasons (around 32 1/2 tropical years). There are two major disadvantages of such a framework, which would clarify why it isn't known ever to have been utilized anyplace on the planet. To begin with, it can't be managed by methods for a cycle (the main cycles known in classical times were the octaeteris (3 intercalations in 8 years) and the enneadecaeteris (7 intercalations in 19 years). Besides, without a cycle it is hard to set up from the quantity of the year (an) on the off chance that it is intercalary and (b) on the off chance that it is intercalary, where precisely in the year the intercalation is found. 

Albeit a few researchers (see list above) guarantee that the blessed months were rearranged about for comfort without the utilization of intercalation, there is no narrative record of the celebrations of any of the sacred months being seen at whatever month other than those they are currently seen in. The Qu'ran (sura 9.37) just alludes to the "deferment" of a holy month. On the off chance that they were rearranged as proposed, one would expect there to be a disallowance against "expectation" also. On the off chance that the celebrations of the sacrosanct months were kept in season by moving them into later months, they would travel through the entire a year in just 33 years. Had this occurred, in any event one author would have referenced it. Sura 9.36 states "Verily, the quantity of months with Allah is a year" and sura 37 alludes to "changing the quantity of months". Such alteration must be affected by intercalation. 

There are various signs that the intercalated schedule was like the Jewish schedule, whose year started in the spring. There are pieces of information in the names of the months themselves: 

Rabi' I - first spring 

Rabi' II - second spring 

Jumada I - first month of dried land 

Jumada II - second month of dried land 

Sha'ban - Arabs "scattered" to discover water 

Ramadan - burned 

Shawwal - female camels "raised" their tails in the wake of calving 

In the intercalated schedule's last year (AD/CE 632), Dhu al-Hijjah related to March. The Battle of the Trench in Shawwal and Dhu'l Qi'dah of AH 5 matched with "cruel winter climate". Military crusades bunched round Ramadan, when the mid year heat had dispersed, and every single battling wa taboo during Rajab, at the stature of summer. The intrusion of Tabak in Rajab AH 9 was hampered by "an excess of sweltering climate" and "dry spell". In AH 1 Muhammad noticed the Jews of Yathrib watching a celebration when he showed up on Monday, 8 Rabi'I. Rabi'I is the third month and in the event that it matched with the third month of the Jewish schedule the celebration would have been the Feast of Weeks, which is seen on the sixth and seventh days of that month.