How many days is the difference?
A Hijri month begins with the new crescent moon, and the time from one new moon to the next averages 29.53 days (29 days, 12 hours and 44 minutes). So a Hijri month is always 29 or 30 days, and 12 of them average 354.37 days.
The Gregorian year follows the Earth’s orbit around the Sun and averages 365.2425 days. The difference is therefore 10.875 days on average, usually rounded to 11.
In any single year the gap is 10, 11 or 12 days, because the Hijri year is 354 or 355 days and the Gregorian year 365 or 366. In the Umm al-Qura calendar for the current Hijri century (1400–1499 AH), 63 years have 354 days and 37 have 355, an average of 354.37 days — almost exactly the astronomical figure.
Quick comparison
| Hijri year | Gregorian year | |
|---|---|---|
| Based on | The Moon (crescent sightings) | The Earth’s orbit around the Sun |
| Months | 12 | 12 |
| Month length | 29 or 30 days | 28 to 31 days |
| Year length | 354 or 355 days | 365 days, 366 in a leap year |
| Month starts | At the crescent sighting, or by calculation as in Umm al-Qura | Fixed dates |
| Day starts | At sunset (in Islamic law) | At midnight |
| New year | 1 Muharram | 1 January |
| Epoch | The Prophet’s ﷺ migration (Hijrah) from Makkah to Madinah, 622 CE | The traditional date of the birth of Jesus |
| Seasons | Months move through the seasons | Stays in step with the seasons |
The Gregorian calendar used today replaced the Julian calendar in 1582. Because the solar year is slightly longer than 365 days, 29 February is added every 4 years, except in century years not divisible by 400: 2000 was a leap year, 2100 will not be.
The Hijri year has 12 months, as the Quran says: “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” (at-Tawbah 9:36). In order: Muharram, Safar, Rabi al-Awwal, Rabi al-Thani (also called Rabi al-Akhir), Jumada al-Awwal (al-Ula), Jumada al-Thani (al-Akhirah), Rajab, Shaban, Ramadan, Shawwal, Dhu al-Qadah and Dhu al-Hijjah. The four sacred months are Dhu al-Qadah, Dhu al-Hijjah, Muharram and Rajab. See every month of this year with its Gregorian dates in the Hijri calendar 1448.
Why does Ramadan come earlier every year?
Ramadan is always the ninth Hijri month, and the Hijri year is about 11 days shorter, so Ramadan starts about 11 days earlier in the Gregorian calendar each year:
| Hijri year | 1 Ramadan (Umm al-Qura) | Earlier than the year before by |
|---|---|---|
| 1447 AH | 18 February 2026 | — |
| 1448 AH | 8 February 2027 | 10 days |
| 1449 AH | 28 January 2028 | 11 days |
| 1450 AH | 16 January 2029 | 12 days |
That is why Ramadan passes through every season in about 33 years: Muslims fasted it in high summer from 2014 to 2016 (it began on 28 June 2014), and it is now moving into winter, starting in December from 1452 AH (26 December 2030). Dates are Umm al-Qura; the actual start of fasting can differ by a day depending on the moon sighting in each country. See how long is left until the next Ramadan with the Ramadan countdown.
33 Hijri years ≈ 32 Gregorian years
33 Hijri years = 33 × 354.37 ≈ 11,694 days, and 32 Gregorian years = 32 × 365.24 ≈ 11,688 days. They differ by only 6 days, which is why this rule is used for quick conversions. In practice, the Hijri count gains one full year on the Gregorian count about every 32½ Gregorian years.
Why is your Hijri age higher?
Because Hijri years are shorter, more of them fit into the same lifetime. Your Hijri age is roughly your Gregorian age × 1.0307, about 3 extra Hijri years per century:
- 30 Gregorian years ≈ 30 years and 11 months in Hijri years.
- 40 Gregorian years ≈ 41 years and 2 months.
- 60 Gregorian years ≈ 61 years and 10 months.
For your exact Hijri age to the day, use the Hijri age calculator.
How to convert a Hijri year to Gregorian
Hijri to Gregorian: multiply the Hijri year by 32, divide by 33, then add 622.
G ≈ H × 32 ÷ 33 + 622
Example: 1448 × 32 ÷ 33 + 622 ≈ 2026. Indeed, 1448 AH began on 16 June 2026 and ends in June 2027.
Gregorian to Hijri: subtract 622, multiply by 33 and divide by 32.
H ≈ (G − 622) × 33 ÷ 32
Example: (2026 − 622) × 33 ÷ 32 = 1447.9, so 2026 contains the end of 1447 AH and the start of 1448 AH.
These formulas only give the year and can be one year off near the start or end of a year, because the two years don’t begin on the same day. To convert a full date, use the Hijri–Gregorian date converter.
When will the two year numbers be equal?
The Hijri year number is currently about 578 behind the Gregorian one, but it grows slightly faster (1.0307 Hijri years per Gregorian year), closing the gap by one year about every 32½ years. At that rate the two numbers meet around 20,874 CE, roughly 19,000 years from now.
When did the Hijri calendar start?
The Arabs used lunar months with these names before Islam, but had no unified count of years. Under the caliphate of Umar ibn al-Khattab, in 17 AH according to the best-known reports (16 AH in others), the Companions agreed to count years from the Prophet’s ﷺ migration from Makkah to Madinah. Sahl ibn Sa‘d said: “They did not count from the Prophet’s mission nor from his death; they counted only from his arrival in Madinah” (al-Bukhari).
They made Muharram the first month even though the migration itself took place in Rabi al-Awwal, because the resolve to migrate followed the pledge of al-‘Aqabah in Dhu al-Hijjah, making Muharram the first new moon after it. 1 Muharram 1 AH corresponds to 16 July 622 CE in the Julian calendar used at the time.
Umm al-Qura or moon sighting?
The Umm al-Qura calendar is Saudi Arabia’s official calendar. It is calculated astronomically in advance, so its dates are known years ahead. The start of Ramadan, Shawwal and Dhu al-Hijjah, however, is announced there after the moon is sighted. In Egypt, Dar al-Ifta announces the start of the Hijri months after the crescent sighting.
That is why a Hijri date can differ by one day between countries, and rarely more. All Daftary tools use Umm al-Qura, the official calendar published in advance.
Frequently Asked Questions
How many days are in a Hijri year?
354 or 355, depending on how many months have 30 days that year; 354.37 on average.
Can a Hijri month have 31 days?
No. A Hijri month has only 29 or 30 days, because the time between two new moons averages 29.53 days.
Does the Hijri calendar have leap years?
No month or days are added to keep it in step with the solar year, which is why the months move through the seasons; Islam abolished the pre-Islamic practice of postponing months (nasi’). In the arithmetical (tabular) Hijri calendar, a 355-day year is called a leap year, and there are 11 of them in every 30 years.
How many Hijri years are in 100 Gregorian years?
About 103. Every 10 Gregorian years are roughly 10 Hijri years and 3 to 4 months.
Why do Hijri dates differ between countries?
Some countries start the month by sighting the crescent and others by astronomical calculation, and the crescent may be seen in one country but not another on the same evening. The difference is usually one day.
What is the current Hijri year?
1448 AH, which began on 16 June 2026 (Umm al-Qura); 1449 AH begins on 6 June 2027. Today’s Hijri date is shown at the top of this page.
Sources
- The Quran: at-Tawbah 9:36 and al-Baqarah 2:189 (“They ask you about the new moons. Say: they are measures of time for the people and for Hajj”).
- Sahih al-Bukhari, Book of the Merits of the Ansar, chapter on the start of dating, hadith 3934 — Dorar (Arabic).
- The Umm al-Qura calendar: every date and year length in this article is calculated from it directly. Our methodology.
- How Does the Hijri Calendar Work? — timeanddate.com.