Instruct: Given a question, retrieve relevant passages that can help answer the question.
Query: What calendar is used by Muslims?
The Islamic, Muslim, or Hijri calendar (Arabic: التقويم الهجري‎ at-taqwīm al-hijrī) is a lunar calendar consisting of 12 lunar months in a year of 354 or 355 days. It is used to determine the proper days of Islamic holidays and rituals, such as the annual period of fasting and the proper time for the pilgrimage to Mecca. The civil calendar of almost all countries where the religion is predominantly Muslim is the Gregorian calendar. Notable exceptions to this rule are Iran and Afghanistan, which use the Solar Hijri calendar. Rents, wages etc. are generally paid by the civil calendar.
The Javanese calendar is used by Javanese people concurrently with two other calendars, the Gregorian calendar and the Islamic calendar. Gregorian calendar is the official calendar of Indonesia while the Islamic calendar is used by Muslims and Indonesian government for religious worship and deciding relevant Islamic holidays. Javanese calendar presently used mostly for cultural events (such as Satu Sura). The present Javanese calendar system is a lunar calendar adopted by Sultan Agung in 1633, based on the Islamic calendar. Previously, Javanese people used a solar system based on the Hindu calendar.
The details included and tracked in an editorial calendar depend upon the steps involved in publishing content for a publication, as well as what is useful to track. Too little or too much data make editorial calendars difficult to maintain and use. Some amount of tweaking of editorial calendar elements, while using the calendar to publish content, is required before they can be truly useful.
The Islamic calendar, Muslim calendar or Hijri calendar (AH) is a lunar calendar consisting of 12 months in a year of 354 or 355 days. It is used to date events in many Muslim-majority countries and determines the proper days on which to observe the annual fast (see Ramadan), to attend Hajj, and to celebrate other Islamic holidays and festivals.
The calendar used by the Punjabi people varies by religions. Historically, the Punjabi Sikhs and Hindus have used the Indian Bikrami (Vikrami) calendar which started in 57 B.C. with King Vikramaditya. Punjabi Muslims use the Arabic Hijri calendar. Some festivals in Punjab, Pakistan are determined by the Punjabi calendar, such as Muharram which is celebrated twice, once according to the Muslim year and again on the 10th of harh. The Bikrami calendar is the one the rural (agrarian) population follows in Punjab, Pakistan.
Guo Shoujing applied mathematics to the construction of calendars. He was one of the first mathematicians in China to work on spherical trigonometry. Gou derived a cubic interpolation formula for his astronomical calculations. His calender, the Shoushi Li (授時暦) or "Calendar for Fixing the Seasons", was disseminated in 1281 as the official calendar of the Yuan dynasty. The calendar may have been influenced solely by the work of Song dynasty astronomer Shen Kuo or possibly by the work of Arab astronomers. There are no explicit signs of Muslim influences in the Shoushi calendar, but Mongol rulers were known to be interested in Muslim calendars. Mathematical knowledge from the Middle East was introduced to China under the Mongols, and Muslim astronomers brought Arabic numerals to China in the 13th century.
The Saka Era was the widely used in Bengal, prior to the arrival of Muslim rule in the region, according to various epigraphical evidence. The Bikrami calendar was in use by the Bengali people of the region. This calendar was named after king Vikramaditya with a zero date of 57 BCE. In rural Bengali communities, the Bengali calendar is credited to "Bikromaditto", like many other parts of India and Nepal. However, unlike these regions where it starts in 57 BCE, the modern Bangladeshi and Bengali calendar starts from 593 CE suggesting that the starting reference year was adjusted at some point.
There are two branches of Islam; the Sunni and the Shi'i. The Sunnis make up about 85-90% of Muslims, but the Ta'zieh tradition is performed by Shi'i Muslims during the first month of the Muslim calendar, Muharram, one of the four sacred months of the Islam calendar. Muharram means forbidden. The Ta'Zieh is performed each year on the 10th day of Muharram, a historically significant day for the Shi'i Muslims because that was the day of Hussein's slaughter. Each year the same story is told, so the spectators know the story very well and know what to expect. However, this does not negatively affect audience levels. In fact, the Ta'zieh welcomes large crowds and the audience members are known to cry each time the story is told in mourning and respect for Hussein.
The Julian calendar was also used in some Muslim countries. The Rumi calendar, the Julian calendar used in the later years of the Ottoman Empire, adopted an era derived from the lunar AH year equivalent to AD 1840, i.e., the effective Rumi epoch was AD 585. In recent years, some users of the Berber calendar have adopted an era starting in 950 BC, the approximate date that the Libyan pharaoh Sheshonq I came to power in Egypt.
It is used by some Muslims in everyday life, particularly in Ismaili communities, believing that this calendar was developed by Ali. It is believed that when Ali drew up this calendar, the previous events of the earlier prophets also fell into line with this calendar. It is their belief that all Fatimid Imams and their Da'is have followed this tradition.
There is evidence of a limited cultural borrowing from the Mozarabs by the Muslim community in Al-Andalus. For instance, the Muslims' adoption of the Christian solar calendar and holidays was an exclusively Andalusi phenomenon. In Al-Andalus, the Islamic lunar calendar was supplemented by the local solar calendar, which were more useful for agricultural and navigational purposes. Like the local Mozarabs, the Muslims of Al-Andalus were notoriously heavy drinkers. Muslims also celebrated traditional Christian holidays sometimes with the sponsorship of their leaders, despite the fact that such fraternisation was generally opposed by the Ulema. The Muslims also hedged their metaphysical bets through the use of Roman Catholic sacraments. 
The Javanese calendar () is the calendar of the Javanese people. It is used concurrently with two other calendars, the Gregorian calendar and the Islamic calendar. The Gregorian calendar is the official calendar of the Republic of Indonesia and civil society, while the Islamic calendar is used by Muslims and the Indonesian government for religious worship and deciding relevant Islamic holidays.
The Jalali calendar is a solar calendar that was used in Persia, variants of which today are still in use in Iran and Afghanistan. In Iran, the Persian names of the zodiac are used while in Afghanistan the original Arabic names are used, also known as the Solar Hijri Calendar. It gains approximately 1 day on the Julian calendar every 128 years. The tropical Jalali calendar (), which inherited some aspects from the Yazdgerdi calendar, was adopted on 15 March 1079 by the Seljuk Sultan Jalal al-Din Malik Shah I (for whom it was named), based on the recommendations of a committee of astronomers, including Omar Khayyam, at the imperial observatory in his capital city of Isfahan. Month computations were based on solar transits through the zodiac. It remained in use for eight centuries. It arose out of dissatisfaction with the seasonal drift in the Islamic calendar which is due to that calendar being lunar instead of solar; a lunar year of 354 days, while acceptable to a desert nomad people, proved to be unworkable for settled, agricultural peoples, and the Iranian calendar is one of several non-lunar calendars adopted by settled Muslims for agricultural purposes (others include the Coptic calendar, the Julian calendar, and the Semitic calendars of the Near East). Sultan Jalal commissioned the task in 1073. Its work was completed well before the Sultan's death in 1092, after which the observatory would be abandoned.
Since 1921, there have been two calendars in use within the Orthodox Church: the Julian Calendar and the Revised Julian Calendar. As of this century there is a thirteen-day difference between the two calendars, so where the former is used, any given fixed date occurs thirteen days later than where the latter is used, "e.g.", Christmas is fixed on December 25, but where the Julian calendar is used, that date falls on what is commonly known as January 7. The date of Pascha, however, is everywhere reckoned using the Julian Calendar, resulting in differing interactions between the Paschal cycle and the fixed cycle, "e.g." the Annunciation may fall as late as Bright Wednesday where the Julian Calendar is used but only as late as the Thursday before Palm Sunday where the revised calendar is used.
Inscriptions of the ancient South Arabian calendars reveal the use of a number of local calendars. At least some of these South Arabian calendars followed the lunisolar system. For Central Arabia, especially Mecca, there is a lack of epigraphical evidence, but details are found in the writings of Muslim authors of the Abbasid era. Some historians maintain that the pre-Islamic calendar used in Central Arabia was a purely lunar calendar similar to the modern Islamic calendar. Others concur that the pre-Islamic calendar was originally a lunar calendar, but suggest that about 200 years before the Hijra it was transformed into a lunisolar calendar, which had an intercalary month added from time to time to keep the pilgrimage within the season of the year when merchandise was most abundant.
With the arrival of the Islamic rule era, the Hijri Islamic calendar became the official calendar of various Sultanates and the Mughal Empire. During the british colonial rule of the Indian subcontinent, the Gregorian calendar was adopted and it is commonly used in the urban areas of India and Nepal. The predominantly Muslim countries of Pakistan and Bangladesh use the Islamic calendar since 1947, but older texts variously included the Bikrami and Gregorian calendar systems. In 2003, the India-based Shiromani Gurdwara Parbandhak Committee of Sikhism adopted the Nanakshahi calendar, a move that continues to be debated. The Vikrami calendar is the official calendar of Nepal.
If the Islamic calendar were prepared using astronomical calculations, Muslims throughout the Muslim world could use it to meet all their needs, the way they use the Gregorian calendar today. But, there are divergent views on whether it is licit to do so.[35]
The revised Nanakshahi calendar was designed by Pal Singh Purewal to replace the Bikrami calendar. The epoch of this calendar is the birth of the first Sikh Guru, Nanak Dev in 1469 and the Nanakshahi year commences on 1 Chet. New Year's Day falls annually on what is March 14 in the Gregorian Western calendar. The start of each month is fixed. According to Kapel (2006), the solar accuracy of the Nanakshahi calendar is linked to the Gregorian civil calendar. This is because the Nanaskhahi calendar uses the tropical year instead of using the sidereal year which is used in the Bikrami calendar or the old Nanakshahi and Khalsa calendars.
Because Muslim holiday are dependent on the Islamic calendar, and—like Christian Easter—move from year to year. Some Muslim holidays are also dependent upon astronomical sightings (e.g.: the observance of moonrise for Ramadan). National commemorations and secular international holidays are fixed on the Gregorian calendar, the standard civil calendar used in Niger as most of the world.
The traditional calendar of the Ottoman Empire was, like in most Muslim countries, the Islamic calendar. Its era begins from the Hijra in 622 CE and each year is calculated using the 12 Arabian lunar months, approximately eleven days shorter than a Gregorian solar year. In 1839, however, a second calendar was put in use for official matters. The new calendar, which was called the Rumi also began by 622, but with an annual duration equal to a solar year after 1840. In modern Turkey, the Gregorian calendar was adopted as the legal calendar, beginning by the end of 1925. The Islamic calendar is still used when discussing dates in an Islamic context.
The Islamic calendar or Hijri calendar, is a lunar calendar consisting of 12 lunar months in a year of 354 or 355 days. It is used to date events in most of the 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. Its epoch is the Hijra (corresponding to AD 622)
With an annual drift of 11 or 12 days, the seasonal relation is repeated approximately each 33 Islamic years.
Shamsuzzaman states, "it is called Bangla san or saal, which are Arabic and Parsee words respectively, suggests that it was introduced by a Muslim king or sultan." In contrast, according to Sengupta, its traditional name is "Bangabda". In the era of the Akbar, the calendar was called as "Tarikh-e-Elahi" (). In the "Tarikh-e-Elahi" version of the calendar, each day of the month had a separate name, and the months had different names from what they have now. According to Banglapedia, Akbar's grandson Shah Jahan reformed the calendar to use a seven-day week that begins on Sunday, and the names of the months were changed at an unknown time to match the month names of the existing Saka calendar. This calendar is the foundation of the calendar that has been in use by the people of Bangladesh.
The Islamic calendar is now used primarily for religious purposes, and for official dating of public events and documents in Muslim countries. Because of its nature as a purely lunar calendar, it cannot be used for agricultural purposes and historically Islamic communities have used other calendars for this purpose: the Egyptian calendar was formerly widespread in Islamic countries, and the Iranian calendar and the 1789 Ottoman calendar (a modified Julian calendar) were also used for agriculture in their countries. In the Levant and Iraq the Aramaic names of the Babylonian calendar are still used for all secular matters. In Morocco, the Berber calendar (another Julian calendar) is still used by farmers in the countryside.[59] These local solar calendars have receded in importance with the near-universal adoption of the Gregorian calendar for civil purposes. The Saudi Arabia uses the lunar Islamic calendar.[60] In Indonesia, the Javanese calendar, created by Sultan Agung in 1633, combines elements of the Islamic and pre-Islamic Saka calendars.
The Javanese calendar is used by the Javanese people concurrently with two other calendars, the Gregorian calendar and the Islamic calendar. The Gregorian calendar is the official calendar of Indonesia, while the Islamic calendar is used by Muslims and Indonesian government for religious worship and deciding relevant Islamic holidays. The Javanese calendar is presently used mostly for cultural events (such as Siji Surå). The Javanese calendar system is currently a lunar calendar adopted by Sultan Agung in 1633, based on the Islamic calendar. Previously, Javanese people used a solar system based on the Hindu calendar.
Due to the somewhat variable nature of the Islamic calendar, in most Muslim countries, the Islamic calendar is used primarily for religious purposes, while the Solar-based Gregorian calendar is still used primarily for matters of commerce and agriculture.