The Islamic calendar, also known as the Hijri calendar, is a lunar calendar used by Muslims worldwide to determine religious observances and events. Unlike the Gregorian calendar, it follows the cycles of the moon rather than the sun, creating a unique rhythm to the Islamic year.
Key Features of the Islamic Calendar
Each month begins with the sighting of the new crescent moon, making months 29 or 30 days long. A Hijri year is about 10-12 days shorter than a solar year.
The calendar starts from 622 CE when Prophet Muhammad (PBUH) migrated from Mecca to Medina (the Hijra). Current year: 1445 AH (After Hijra).
Consists of 12 lunar months totaling 354-355 days. Four months are sacred: Dhul-Qa'dah, Dhul-Hijjah, Muharram, and Rajab.
Islamic months rotate through the solar year, so Ramadan and Hajj occur in different seasons over a 33-year cycle.
Traditional method relies on actual moon observation, though astronomical calculations are increasingly used alongside sightings.
Determines timing of Ramadan, Hajj, Eid celebrations, and other Islamic observances. Not used for agriculture or commerce in most Muslim countries.
The Islamic Months
A sacred month marking the Islamic New Year. The 10th day (Ashura) commemorates Prophet Musa's salvation and Imam Hussain's martyrdom.
Traditionally associated with the Prophet's illness and recovery. Some pre-Islamic superstitions about this month were abolished in Islam.
Birth month of Prophet Muhammad (PBUH). Many Muslims celebrate Mawlid, though practices vary among Islamic schools.
Also called Rabi' al-Akhir. Several important battles in Islamic history occurred during this month.
Meaning "the first dry month." Historically when water would freeze in Arabia. Battle of Muta took place this month.
The second dry month. Death of Khadija (RA) and Abu Talib occurred in this month (Year of Sorrow).
A sacred month. The 27th night is traditionally observed as the night of Isra and Mi'raj (the Prophet's night journey).
The 15th night is Laylat al-Bara'ah (Night of Forgiveness). The Prophet would fast frequently this month before Ramadan.
The month of fasting, Quran revelation, and increased worship. Contains Laylat al-Qadr (Night of Power).
First day is Eid al-Fitr. Fasting six days this month is equivalent to fasting the entire year.
A sacred month when fighting was traditionally prohibited. The Treaty of Hudaybiyyah was signed this month.
The sacred month of Hajj. The first ten days are the most virtuous days of the year. Eid al-Adha occurs on the 10th.
Etymology of Month Names
- Muharram: "Sacred" - One of the four sacred months
- Safar: "Empty" - Possibly referring to empty houses as people traveled after Muharram
- Rabi' al-Awwal/Thani: "First/Second spring" - Originally in spring season
- Jumada al-Awwal/Thani: "First/Second freeze" - When water would freeze
- Rajab: "Respect" - Another sacred month
- Sha'ban: "Scatter" - Tribes would scatter to find water
- Ramadan: "Burning heat" - Originally a summer month
- Shawwal: "Raise" - Female camels would raise their tails after mating
- Dhul-Qa'dah: "The one of truce" - No fighting during this sacred month
- Dhul-Hijjah: "The one of pilgrimage" - Month of Hajj
Islamic vs. Gregorian Calendar
| Feature | Islamic Calendar | Gregorian Calendar |
|---|---|---|
| Type | Purely lunar | Solar |
| Year Length | 354-355 days | 365-366 days |
| Months | Fixed at 12, based on moon cycles | 12, with fixed lengths unrelated to moon |
| Leap Years | 11 days shorter each year, no leap days | Leap day every 4 years (Feb 29) |
| Month Length | 29 or 30 days (based on moon sighting) | 28-31 days (fixed) |
| Epoch | 622 CE (Hijra) | Traditional birth of Jesus |
| Religious Events | Rotate through seasons every 33 years | Fixed seasons (Christmas always in winter) |
| Usage | Primarily religious purposes | Civil calendar worldwide |
Calculating Important Islamic Dates
Because the Islamic calendar is lunar, dates shift about 10-11 days earlier each Gregorian year. Here are some methods to determine when Islamic months begin:
Actual observation of the new crescent moon by naked eye after sunset on the 29th day of the Islamic month. Still practiced in many Muslim countries.
Using scientific calculations to predict the new moon's visibility. Some organizations and countries use this method exclusively.
Some use predetermined alternating 29/30 day months with complex leap year rules to approximate the lunar cycle (e.g., Umm al-Qura calendar).
Practical Implications
Ramadan Rotation
Because the Islamic year is shorter than the solar year, Ramadan moves through the seasons:
- 2020-2023: Spring (Northern Hemisphere)
- 2024-2027: Winter
- 2028-2031: Autumn/Fall
- 2032-2035: Summer
This means fasting hours vary significantly depending on location and season.
Eid Dates
Eid al-Fitr and Eid al-Adha dates vary by country based on moon sighting methods:
- Some countries follow local sightings
- Others follow sightings in Mecca or neighboring countries
- Some use astronomical calculations exclusively
Living With Both Calendars
- Use Gregorian calendar for work/school and Hijri for religious observances
- Digital calendars often support both systems simultaneously
- Many Muslim countries use both calendars officially
- Financial institutions in Islamic countries often use Hijri dates for Islamic banking products
- Historical Islamic events are typically dated in Hijri years