Hijri Calendar Converter

History of the Islamic Calendar

The Islamic (Hijri) calendar was officially established by Caliph Umar ibn al-Khattab (may Allah be pleased with him) in 638 CE (17 AH), during a consultation with the Companions of the Prophet. The need arose when Umar received a document dated simply "Sha'ban" without specifying the year, making it unclear which year was meant. After consulting with Ali ibn Abi Talib, Uthman ibn Affan, and other senior Companions, they unanimously agreed to start the calendar from the Hijra — the migration of Prophet Muhammad (peace be upon him) from Mecca to Medina in 622 CE. This event was chosen not because it was the Prophet's birth or the beginning of revelation, but because it marked the establishment of the first Islamic state and community in Medina. It represented a turning point where Muslims transitioned from persecution to sovereignty, from weakness to strength. The months themselves predated Islam and were already in use among the Arabs, but the Hijri era gave them a fixed starting point. The choice of Muharram as the first month (rather than Rabi al-Awwal, the actual month of the Hijra) was because it followed the month of Dhul Hijjah and the Hajj season, providing a natural beginning to the year.

Structure of the Hijri Calendar

The Hijri calendar consists of 12 lunar months, each lasting 29 or 30 days depending on the sighting of the new crescent moon (hilal). A lunar year is approximately 354 days (or 355 in a leap year), making it about 10 to 12 days shorter than the Gregorian solar year of 365 days. This difference means that Islamic dates move forward through the seasons over a cycle of approximately 33 years. For example, Ramadan may fall in summer one decade and in winter the next. This cyclical movement ensures that Muslims in all parts of the world experience fasting in both long and short days over their lifetime, reflecting divine justice. The beginning of each month is traditionally determined by the physical sighting of the new crescent moon. When the moon is sighted on the 29th evening of a month, the new month begins the next day. If it is not sighted, the current month completes 30 days. Some countries now use astronomical calculations (the Umm al-Qura calendar in Saudi Arabia, for instance) for civil purposes, while still relying on moon sighting for religious observances. The months alternate between 29 and 30 days, though this is not fixed and depends on actual lunar observations.

The Sacred Months in Islam

Four months of the Islamic calendar are designated as sacred (Hurum) in the Quran: "Indeed, the number of months with Allah is twelve months in the register of Allah from the day He created the heavens and the earth; of these, four are sacred" (Quran 9:36). These four sacred months are: Dhul Qi'dah (11th), Dhul Hijjah (12th), Muharram (1st), and Rajab (7th). Three of them are consecutive (Dhul Qi'dah, Dhul Hijjah, and Muharram) and one stands alone (Rajab). During these months, fighting and warfare were traditionally forbidden in pre-Islamic Arabia, and Islam affirmed and elevated this prohibition. The Prophet (peace be upon him) said: "Time has come back to its original state which it had when Allah created the heavens and the earth. The year consists of twelve months, four of which are sacred: three consecutive — Dhul Qi'dah, Dhul Hijjah, and Muharram — and Rajab of Mudar, which comes between Jumada and Sha'ban" (Sahih al-Bukhari). Good deeds during these months carry greater reward, and sins committed during them are considered more severe.

Important Islamic Dates Throughout the Year

The Islamic calendar is rich with significant dates that Muslims observe. Ramadan (9th month) is the most well-known, being the month of obligatory fasting from dawn to sunset, culminating in Laylat al-Qadr (the Night of Power), which is better than a thousand months (Quran 97:3) and is traditionally sought in the last ten nights of Ramadan. Eid al-Fitr (1st Shawwal) celebrates the end of Ramadan with communal prayers, charity, and festivities. Eid al-Adha (10th Dhul Hijjah) commemorates Prophet Ibrahim's willingness to sacrifice his son and coincides with the Hajj pilgrimage. The Day of Arafah (9th Dhul Hijjah) is considered the best day of the year; fasting on this day expiates sins of the previous and coming year (Sahih Muslim). Ashura (10th Muharram) marks the day Allah saved Prophet Musa and the Children of Israel; fasting on this day expiates the sins of the previous year. Mawlid an-Nabi (12th Rabi al-Awwal) commemorates the birth of Prophet Muhammad (peace be upon him), though scholars differ on how to observe it. Isra wal Mi'raj (27th Rajab) commemorates the Prophet's miraculous night journey from Mecca to Jerusalem and his ascension to the heavens.

How the Hijri-Gregorian Conversion Works

Converting between the Hijri and Gregorian calendars is not a simple matter of adding or subtracting a fixed number of years, because the two calendars are based on fundamentally different astronomical cycles. The Gregorian calendar follows the solar year (365.25 days), while the Hijri calendar follows the lunar year (354.37 days). The difference of approximately 10.88 days per year means that 33 Hijri years roughly equal 32 Gregorian years. Mathematical algorithms can provide approximate conversions based on average lunar month lengths, but precise dates may vary by one or two days from actual observed dates. This is because the actual beginning of each Islamic month depends on the physical sighting of the crescent moon, which is influenced by atmospheric conditions, geographical location, and other factors. Different Muslim communities may begin the month on different days depending on local moon sighting. Our converter uses the tabular Islamic calendar algorithm, which provides a close approximation suitable for general planning purposes. For exact religious dates (like the beginning of Ramadan), always follow your local Islamic authority's moon sighting announcement.

Practical Uses of the Hijri Calendar Today

The Hijri calendar remains essential in the daily lives of Muslims worldwide. It determines the month of Ramadan for fasting, the exact days of Hajj pilgrimage (8th-13th Dhul Hijjah), the dates of the two Eid celebrations, and other religious observances like the fasting of Ashura, the Day of Arafah, and the white days (13th, 14th, 15th of each lunar month). It is also used for calculating the Zakat year (Hawl), determining the Iddah period (waiting period after divorce or death of a spouse), and establishing business and legal contracts in many Muslim-majority countries. Saudi Arabia, the home of the two holy mosques, uses the Hijri calendar as its official civil calendar. Many other Muslim countries maintain a dual calendar system, using the Gregorian calendar for business and the Hijri calendar for religious purposes. For Muslims living in non-Muslim countries, knowing the Hijri date helps them stay connected to the rhythms of Islamic life, plan for Ramadan and Eid, and fulfill time-sensitive religious obligations.

The Islamic Months