What is the Hijri calendar and how does it differ from the Gregorian?
The Hijri calendar (Islamic lunar calendar) tracks the moon, not the sun. Each month begins when the new moon is sighted; each year is 354 or 355 days, ~11 days shorter than the Gregorian solar year. This means Islamic months drift backward through the seasons over time. Ramadan in 2026 falls in March; in 2050 it'll be in November.
For checking Islamic prayer times in any city today, the Islamic prayer time page handles the calendar conversions.
How it works
The Hijri calendar has 12 months, each 29 or 30 days. The year has 12 × 29.5 ≈ 354 days. In leap years (11 out of every 30), one day is added.
The year began in 622 CE, when Muhammad migrated from Mecca to Medina (the Hijra). That event marks year 1 AH (After Hijra). The current Hijri year (2026 CE) is approximately 1448 AH.
The 12 months in order:
1. Muharram
2. Safar
3. Rabi' al-Awwal (the month of Muhammad's birthday)
4. Rabi' al-Thani
5. Jumada al-Awwal
6. Jumada al-Thani
7. Rajab
8. Sha'ban
9. Ramadan (the month of fasting)
10. Shawwal
11. Dhu al-Qi'dah
12. Dhu al-Hijjah (the month of Hajj)
Why dates shift each year
A Gregorian year is 365.25 days. A Hijri year is 354.36 days. The difference is about 11 days.
So:
- Ramadan 2026: starts mid-February
- Ramadan 2027: starts early February (11 days earlier)
- Ramadan 2030: starts mid-January
- Ramadan 2050: starts early November
Over a 33-year cycle, Ramadan drifts through every season.
Sighting vs calculation
Two approaches to determining month start:
Visual sighting (rūʾyah). Wait for the new moon to be physically observable on the western horizon at sunset. Authoritative in classical fiqh; still required for major dates in Saudi Arabia, parts of South Asia.
Astronomical calculation. Use modern astronomy to predict when the new moon will be visible. Used by Turkey, Egypt (often), and many international communities.
Both methods are recognized as valid by various scholars. Different communities use different conventions.
The result: the start of a month can vary by 1-2 days between countries that use different methods. Eid al-Fitr 2026 might fall on March 19 in some countries and March 20 in others.
Civil vs religious calendar use
Most Muslim-majority countries use the Gregorian calendar for civil purposes (banking, contracts, secular events). The Hijri calendar is used for:
- Religious observances (Ramadan, Eid, Hajj)
- Religious documents
- Historical references
- Some date-stamping in older legal contexts
Saudi Arabia and Iran are exceptions. Saudi Arabia officially uses the Hijri calendar for many government purposes (gradually shifting; 2016 reform reduced its civil use). Iran uses the Solar Hijri calendar (Persian/Iranian calendar), which is solar but anchored to the Hijra.
Notable dates
1 Muharram (Islamic New Year). Marks the start of the Hijri year. Less celebrated than secular Gregorian New Year; some Muslims observe it as a day of reflection.
10 Muharram (Ashura). Significant in both Sunni and Shia traditions, but for different historical reasons.
12 Rabi' al-Awwal (Mawlid). Birthday of the Prophet Muhammad. Celebrated by many Muslims (some traditions discourage observance).
27 Rajab (Lailat al-Mi'raj). The Night Journey.
Shaban 15 (Lailat al-Bara'ah). Often observed with prayer.
Ramadan (entire month). Fasting from dawn to sunset.
1 Shawwal (Eid al-Fitr). Festival ending Ramadan.
8-13 Dhu al-Hijjah. Hajj period.
10 Dhu al-Hijjah (Eid al-Adha). Festival of Sacrifice.
How modern Muslims navigate
Most observant Muslims use:
- A standard Gregorian calendar for daily life (work, family events)
- An Islamic calendar app or printed Hijri calendar for religious observances
- Astronomical calculation for advance planning, with confirmation from local mosque sighting
The dual-calendar life is normal. Apps like Muslim Pro, Athan, and various locale-specific apps all show both Gregorian and Hijri dates.
Calculating today's Hijri date
Most apps and websites convert automatically. The Islamic prayer time page shows Hijri date at the top. Online converters (search "Gregorian to Hijri") give precise conversions.
Manual calculation is hard because of the leap-year rules and the sighting variability. Stick with apps.
Why the calendar matters
Beyond religious observance, the Hijri calendar affects:
Business in Muslim countries. Saudi Arabia has Friday as the weekend, with Saturday-Sunday as work days; some other Muslim-majority countries have Friday-Saturday weekend. Date stamping on documents may use either or both calendars.
International coordination. During Ramadan, fasting affects working hours, productivity, and meeting schedules across the Muslim world. Companies operating in Muslim-majority regions adjust schedules.
Personal observance. Knowing the current Hijri date is essential for personal religious practice — prayers, fasts, charity timing.
FAQ
Is the Hijri calendar the same in all Muslim countries?
The structure is the same — 12 months of 29-30 days. But the start of each month can vary by 1-2 days based on whether countries use moon sighting or astronomical calculation. Saudi Arabia, Egypt, Pakistan, Indonesia all sometimes start the same month on different days.
What about the Solar Hijri calendar (Iran)?
A different system. The Solar Hijri (Persian) calendar is solar (365 days), anchored to the Hijra. It's the official calendar of Iran and Afghanistan. Months are different from the lunar Hijri.
Does the Hijri calendar account for the seasons?
No — that's the point. It's purely lunar, ignoring solar seasons entirely. This is why Ramadan can fall in any season over time.
How do Muslims plan business or travel in advance?
Apps and printed calendars give Hijri dates 1-2 years in advance with reasonable accuracy. Beyond that, predictions can vary by a day due to moon-sighting variability.
What's the difference between AH and CE/AD years?
AH = After Hijra (since 622 CE). CE = Common Era. So 1448 AH = 2026 CE roughly, but they don't align exactly because of the different year lengths. There are many converters online for any date.
Why does Ramadan come earlier each year?
Because the Hijri year is ~11 days shorter than the Gregorian year. Each year, the same Hijri date falls about 11 days earlier in the Gregorian calendar. Over 33 years, the cycle completes.
Bottom line
The Hijri calendar is the lunar Islamic calendar — 354-355 days per year, 12 months of 29-30 days each, with dates determined by moon sighting or astronomical calculation. It's used worldwide for Islamic religious observance and is the official calendar of a few countries. Dates drift backward through the Gregorian calendar by ~11 days each year.
For Hijri-date conversions and Islamic prayer times in any city, the Islamic prayer time page handles both.