The Islamic calendar: 12 months and their significance

How the Hijri calendar works

The Islamic calendar is a purely lunar calendar. Each month begins with the sighting of the new crescent moon and lasts either 29 or 30 days, depending on when the next crescent is sighted. This means the Islamic year contains either 354 or 355 days, approximately 10 to 11 days fewer than the Gregorian solar year of 365 or 366 days.

The practical consequence of this shorter year is that Islamic observances are not tied to any particular season. Ramadan, Hajj, and every other Hijri observance rotates backward through the Gregorian calendar by approximately 10 days per year. Over a period of roughly 33 Gregorian years, any given Islamic event will have occurred in every season. A Muslim alive for 66 years will have experienced Ramadan twice in every season of the Gregorian year.

This is in contrast to lunar-solar calendars such as the Hebrew or Chinese calendar, which add intercalary months periodically to keep the calendar aligned with the solar year. The Islamic calendar makes no such adjustment. The Prophet prohibited the pre-Islamic Arabian practice of adding an extra month (nasi') to realign the lunar calendar, and this prohibition is referenced in Quran 9:37. The result is a calendar of pure lunar months, unmoored from any solar anchor.

Determining the start of each month has historically been done by physical moon sighting, and scholarly differences remain today about whether it is permissible to use astronomical calculation to predict the crescent in advance, or whether physical sighting is required. Different Muslim communities and countries resolve this differently, which is why Ramadan and Eid can begin on different days in different parts of the world even within the same Gregorian calendar date.

Origin: the Hijra of 622 CE

The Islamic calendar begins from the year of the Prophet Muhammad's migration (hijra) from Mecca to Medina. This event occurred in what the Gregorian calendar records as 622 CE. The migration is considered the founding moment of the Muslim community as a polity, and it was selected as the starting point of the Islamic year by the caliph Umar ibn al-Khattab during his caliphate.

The calendar is therefore called the Hijri calendar (AH, for Anno Hegirae, "year of the Hijra"). The year 2026 CE corresponds approximately to 1447 AH, though the exact correspondence shifts depending on the time of year, since the Hijri and Gregorian years begin at different points.

The first month of the Islamic year is Muharram, not the month of the Hijra itself. The selection of Muharram as the starting month was a decision made by Umar's committee based on existing Arabian convention for the calendar's organization, with the year being anchored to the Hijra event even though the Hijra actually took place in Rabi al-Awwal.

The four sacred months

Quran 9:36 states: "Indeed, the number of months with Allah is twelve lunar months in the register of Allah from the day He created the heavens and the earth; of these, four are sacred. That is the correct religion, so do not wrong yourselves during them."

The four sacred months are identified in prophetic hadith as Dhul Qa'dah, Dhul Hijjah, Muharram, and Rajab. Three of these four fall consecutively (Dhul Qa'dah, Dhul Hijjah, and Muharram), and Rajab falls alone as the seventh month.

In pre-Islamic Arabia, these months had truce status: tribes that were in conflict were expected to observe a ceasefire so that people could travel safely for pilgrimage and trade. Islam affirmed the sanctity of these months and attached to them a heightened spiritual significance. The phrase "do not wrong yourselves during them" is understood by scholars as a special counsel to avoid sin and increase worship during these months. Committing sin during the sacred months is considered more serious in its spiritual weight, just as performing good deeds carries additional reward.

1. Muharram (مُحَرَّم)

Meaning: "Forbidden" or "sacred." The name itself reflects the month's status as one of the four sacred months.

Muharram is the first month of the Islamic year and one of the four months in which Allah has specifically declared sanctity. The most significant day in this month is the 10th, known as Ashura (from the Arabic word for "ten").

The fast of Ashura has a well-established basis in the Sunnah. When the Prophet arrived in Medina, he observed that the Jewish community was fasting on this day. He was informed that they fasted to commemorate the day Allah saved Moses and the Children of Israel from Pharaoh. The Prophet said, "We have more right to Moses than you," and fasted that day, instructing his companions to do the same. The hadith recording this is found in Sahih Bukhari and Sahih Muslim. Fasting on Ashura expiates the sins of the previous year, according to a hadith in Sahih Muslim.

The Prophet also expressed the intention to fast on the 9th of Muharram in addition to the 10th in order to differ from Jewish practice, though he passed away before the following year's Muharram. Scholars therefore recommend fasting the 9th and 10th together, or the 10th and 11th.

Muharram also holds significance for Shia Muslims as the month of mourning for the martyrdom of Husayn ibn Ali at Karbala (61 AH), though the ritual observances differ markedly between Sunni and Shia practice.

2. Safar (صَفَر)

Meaning: Derived from a root related to "empty" or "yellow," possibly referring to the time when homes were left empty as men departed for travel or war in ancient Arabia. Another interpretation connects it to the yellow color of autumn leaves at the time this month once occurred.

Safar has no specific obligatory or strongly recommended acts of worship designated for it. In pre-Islamic Arabian culture, Safar carried superstitious associations of bad luck. The Prophet explicitly rejected this superstition. A hadith in Sahih Bukhari quotes the Prophet as saying there is no such thing as the ill-omen of Safar (among other pre-Islamic superstitions he named). This rejection is an important example of Islam's systematic dismantling of pre-Islamic superstitious beliefs about time and fortune.

Muslims are counseled to treat Safar like any other month and to avoid the cultural habit of considering it unlucky, which persists in some Muslim communities today despite its explicit rejection in the Sunnah.

3. Rabi al-Awwal (رَبِيع الأَوَّل)

Meaning: "The first spring" or "the first pasture." The name reflects ancient Arabian seasonal naming conventions.

Rabi al-Awwal is the month of the Prophet's birth, according to the most widely held scholarly opinion, which places it on the 12th of Rabi al-Awwal. The same date is also traditionally associated with the Prophet's death, which occurred in 11 AH. The convergence of birth and death on the same calendar date carries its own poignancy for many Muslims.

The observance known as Mawlid al-Nabi, which commemorates the Prophet's birth, falls in this month. The question of whether celebrating Mawlid is permissible is a genuine and long-standing scholarly difference. Scholars who permit it argue that expressing joy at the Prophet's birth and using the occasion to learn about his life and character is praiseworthy. Scholars who consider it an innovation argue that the Prophet and his companions did not mark the birthday as a specific observance, and that introducing it as a practice adds to the religion what was not part of it. Both positions have serious scholarly grounding, and Muslims follow their scholars and communities on this question.

The Prophet's migration (hijra) from Mecca to Medina also took place in Rabi al-Awwal, arriving in Medina in the same month, though the year of the Hijri calendar is anchored to the year of that event rather than the specific month.

4. Rabi al-Thani (رَبِيع الثَّانِي)

Meaning: "The second spring" or "the second pasture." Also referred to as Rabi al-Akhir ("the last spring").

Rabi al-Thani has no specific major Islamic observances designated for it. It is a month in which the general counsel of worship, remembrance, and good character applies, as it does throughout the year. For communities that observe Mawlid, some extend the celebrations into Rabi al-Thani, though the 12th of Rabi al-Awwal is the central date.

5. Jumada al-Ula (جُمَادَى الأُولَى)

Meaning: "The first of the frozen" or "the first arid [month]." The name derives from a root associated with freezing or drought, reflecting the conditions during which these months once fell in the Arabian Peninsula when the calendar was aligned with the solar year in ancient times.

Like Rabi al-Thani, Jumada al-Ula has no specific obligatory observances. It is a month of ordinary religious life, with the general encouragement to maintain consistent worship, recitation of Quran, and dhikr.

6. Jumada al-Akhira (جُمَادَى الآخِرَة)

Meaning: "The last of the frozen" or "the last arid [month]." Also referred to as Jumada al-Thaniya ("the second Jumada").

Jumada al-Akhira is notable in Islamic history as the month of the birth of Fatimah al-Zahra, the daughter of the Prophet, according to one historical tradition. No specific acts of worship are designated for this month. The month also marks the approach of Rajab, one of the four sacred months, and some Muslims begin to mentally prepare for the spiritual season of Rajab, Sha'ban, and Ramadan that follows.

7. Rajab (رَجَب)

Meaning: From a root meaning "to venerate" or "to respect." The name reflects the month's pre-Islamic and Islamic status as one of the four sacred months.

Rajab is one of the four sacred months mentioned in Quran 9:36. Its sanctity predates Islam; in pre-Islamic Arabia, it was a month when fighting was forbidden and pilgrimage travel was safe. Islam affirmed its elevated status.

The night of Isra wal-Miraj, the Prophet's night journey from Mecca to Jerusalem and his ascension through the heavens, is placed in Rajab by many Islamic scholars, though the exact date is not definitively established in the hadith literature and scholars differ on it. The event itself is established beyond doubt; what is uncertain is precisely when in the Hijri calendar it occurred. The 27th of Rajab is the date most commonly observed in Muslim communities as the night of Isra wal-Miraj, though other dates in different months have been proposed by scholars.

Fasting in Rajab is considered praiseworthy given its status as a sacred month. The Prophet is reported to have fasted during the sacred months, though there is no specific hadith designating a particular number of fasts for Rajab alone. Excessive fasting in Rajab to the point of treating it as equal to Ramadan is considered by some scholars to be an innovation, while maintaining moderate voluntary fasting consistent with the month's sacred status is widely accepted.

8. Sha'ban (شَعْبَان)

Meaning: From a root meaning "to branch" or "to spread out," possibly reflecting a time when Arab tribes dispersed to find water sources. Some scholars interpret it as the month when goodness spreads or branches out in preparation for Ramadan.

Sha'ban holds a special place in the Sunnah. A hadith in Sahih Muslim (1156), narrated by Aisha, states: "The Messenger of Allah used to fast until we thought he would never stop fasting, and then he would not fast until we thought he would never fast. I never saw the Messenger of Allah complete a month of fasting except Ramadan, and I never saw him fast more in any month than he did in Sha'ban." In another narration she asked him why he fasted so much in Sha'ban, and he explained that it is a month that people neglect, a month between Rajab and Ramadan, and a month in which deeds are raised to Allah, and he wished his deeds to be raised while he was fasting.

Increasing voluntary fasting in Sha'ban is therefore established sunnah practice, particularly in the first half of the month. The Prophet is also reported to have warned against beginning new voluntary fasts in the second half of Sha'ban once it has begun, to avoid entering Ramadan in a weakened state. Scholars differ on the exact application of this counsel.

The 15th night of Sha'ban, known as Laylat al-Bara'ah ("the night of emancipation") or Shab-e-Barat in South Asian communities, is considered by some scholars to be a night of special significance in which sins are forgiven and destinies written. The hadith supporting this night's special status are considered weak by some scholars of hadith while others consider them sufficient to justify special worship. This is another area of genuine scholarly difference, and Muslims follow their scholars on this question.

9. Ramadan (رَمَضَان)

Meaning: From a root meaning "intense heat" or "burning," reflecting either the scorching heat of the season when this month once fell, or a spiritual sense of burning away sins. It is also said to derive from "ramad," meaning the heated ground.

Ramadan is the ninth and most sacred month of the Islamic calendar. It is the month in which fasting from dawn to sunset is obligatory upon every adult Muslim who is able, as established in Quran 2:183-185. The opening of that passage states: "O you who have believed, decreed upon you is fasting as it was decreed upon those before you that you may become righteous."

Ramadan is also the month in which the Quran was first revealed, as stated in Quran 2:185: "The month of Ramadan is that in which the Quran was revealed, as guidance for the people and clear proofs of guidance and criterion." This dual significance, obligatory fasting and the month of Quranic revelation, makes Ramadan the spiritual centerpiece of the Islamic year.

The last ten nights of Ramadan contain Laylat al-Qadr ("the Night of Power" or "the Night of Decree"), described in Surah Al-Qadr as better than a thousand months. The Prophet encouraged spending the last ten nights of Ramadan in increased worship, prayer, and i'tikaf (spiritual retreat in the mosque). Laylat al-Qadr is most commonly sought on the odd nights of the last ten days, particularly the 27th night, though its exact date is deliberately concealed.

The month ends with Eid al-Fitr on the 1st of Shawwal, one of the two major Islamic celebrations.

10. Shawwal (شَوَّال)

Meaning: From a root meaning "to raise" or "to carry," possibly from the Arabic word for a she-camel raising her tail when pregnant. The month was associated historically with a period of movement.

Shawwal begins with Eid al-Fitr, the celebration marking the end of Ramadan. The 1st of Shawwal is a day of celebration, communal prayer, and gratitude for completing the fast of Ramadan.

The most significant voluntary practice in Shawwal is fasting six days. A hadith in Sahih Muslim states: "Whoever fasts Ramadan and then follows it with six days of Shawwal, it will be as if he fasted the entire year." Scholars explain this by the principle that each good deed is multiplied by ten, so fasting the 30 days of Ramadan (worth 300 days) plus the 6 days of Shawwal (worth 60 days) equals 360 days, approximately a full year. These six fasts can be observed consecutively beginning on the 2nd of Shawwal, or spread throughout the month.

Shawwal was also the month of the Battle of Uhud (3 AH) and is historically the month in which the Prophet contracted his marriage to Aisha, giving the month an association with new beginnings in the Islamic calendar.

11. Dhul Qa'dah (ذُو القَعْدَة)

Meaning: "The one of sitting" or "the month of rest." The name reflects the pre-Islamic convention of refraining from travel and combat in preparation for pilgrimage.

Dhul Qa'dah is one of the four sacred months. It immediately precedes the month of Hajj pilgrimage, and historically it was the month during which pilgrims would begin their journey toward Mecca. Fighting was forbidden so that travel would be safe. The month retains its sacred status in Islam.

No specific voluntary acts of worship are uniquely designated for Dhul Qa'dah beyond those that apply to all sacred months. The general counsel of the four sacred months applies: increased worship, avoidance of sin, and preparation for the spiritual significance of the month that follows.

Dhul Qa'dah is also historically significant as the month in which the Hudaybiyyah peace treaty between the Prophet and the Quraysh was concluded (6 AH), described in the Quran as "a clear victory" (Surah Al-Fath, 48:1).

12. Dhul Hijjah (ذُو الحِجَّة)

Meaning: "The one of pilgrimage." The name directly references the Hajj, the annual pilgrimage to Mecca that takes place in this month.

Dhul Hijjah is one of the four sacred months and the last month of the Islamic year. It contains some of the most significant days in the Islamic calendar.

The first ten days of Dhul Hijjah are described in a hadith as the best days of the year for performing good deeds. A hadith in Sahih Bukhari (969) reports the Prophet saying: "There are no days in which righteous deeds are more beloved to Allah than these ten days." The companions asked whether even jihad in the path of Allah was surpassed, and the Prophet confirmed that even that was surpassed except for a person who goes out with his life and wealth and does not return. The Prophet counseled increasing in takbir (saying Allahu Akbar), tahlil (saying La ilaha illallah), and tahmid (saying Alhamdulillah) during these days.

The Day of Arafah (9th of Dhul Hijjah) is considered the pinnacle of Hajj and one of the most significant days of the Islamic year. Pilgrims performing Hajj stand on the plain of Arafah in an act of supplication that is described as the essential pillar of Hajj ("Hajj is Arafah," as the hadith states). For Muslims not performing Hajj, fasting on the Day of Arafah is highly recommended. A hadith in Sahih Muslim states that fasting on this day expiates the sins of the previous year and the coming year.

Eid al-Adha (10th of Dhul Hijjah) is the second of the two major Islamic celebrations. It commemorates the willingness of Ibrahim to sacrifice his son in obedience to Allah's command, and Allah's provision of a ram as a substitute. The ritual slaughter of livestock (udhiyah or qurbani) is a sunnah practice for those who are able, and the meat is distributed among family, neighbors, and the poor. The 10th, 11th, 12th, and 13th of Dhul Hijjah are collectively known as the days of Tashreeq.

Hajj takes place in Dhul Hijjah, spanning from the 8th to the 13th of the month for those performing the pilgrimage. Hajj is one of the five pillars of Islam and is obligatory once in a lifetime for every Muslim who is physically and financially able. It draws millions of pilgrims from around the world each year to Mecca and its surrounding sites.

Dhul Hijjah closes the Islamic year, completing the cycle of 12 lunar months that began with Muharram. The calendar then renews with the sighting of the crescent moon for the following year's Muharram.

FAQ

How do I convert a Hijri date to a Gregorian date?

Because the Islamic lunar year is approximately 10 to 11 days shorter than the Gregorian solar year, there is no simple arithmetic conversion. Online Hijri-to-Gregorian converters handle the calculation correctly and are the most reliable approach for specific date conversions. Prayer apps including FivePrayer display the current Hijri date alongside the Gregorian date, which is a convenient daily reference.

Why do different Muslim countries start Ramadan on different days?

The Islamic month begins with the sighting of the new crescent moon. Because sightability of the crescent depends on geographical location, atmospheric conditions, and local methodology (physical sighting versus astronomical calculation), different countries can differ by one or even two days. Some Muslim-majority countries follow the announcement of Saudi Arabia, while others use local moon sighting committees. This long-standing difference is a matter of ongoing scholarly discussion rather than a settled matter.

Is there an Islamic month equivalent to a new year celebration?

Muharram is the first month of the Islamic year, and the 1st of Muharram marks the Islamic new year. Unlike secular new year celebrations, there is no specific religious observance attached to this date beyond what applies to all of Muharram as a sacred month. The Prophet did not designate the Islamic new year as a festival. Some Muslims mark it quietly with reflection on the year past and intentions for the year ahead, while others treat it as an ordinary day.

Which months are best for voluntary fasting?

Based on the Sunnah, the most recommended months for voluntary fasting are Sha'ban (the Prophet fasted more in this month than any other besides Ramadan, per Sahih Muslim 1156), Muharram (the Prophet called it the best voluntary fast after Ramadan), and Shawwal (the six fasts of Shawwal). The four sacred months (Muharram, Rajab, Dhul Qa'dah, and Dhul Hijjah) are also generally recommended for increased voluntary worship including fasting. The 9th of Dhul Hijjah (Arafah) is specifically recommended for non-pilgrims.

What is the significance of Laylat al-Qadr?

Laylat al-Qadr (the Night of Power) falls in the last ten days of Ramadan and is described in Surah Al-Qadr as better than a thousand months. It is the night on which the Quran began to be revealed and on which, according to traditional belief, angels descend and decrees for the coming year are determined. The Prophet said it is most likely found on one of the odd nights of the last ten nights of Ramadan. Muslims spend these nights in increased prayer, supplication, and recitation of Quran.