The Hijri calendar (al-taqwīm al-hijrī) is the Islamic calendar used to determine religious dates such as Ramadan, Eid al-Fitr, Eid al-Adha and the Hajj season. It is also the official civil calendar in Saudi Arabia for many purposes, and is widely shown alongside the Gregorian date across the Muslim world. Because it follows the moon rather than the sun, its dates drift through the seasons. This guide explains the structure, the different ways months are determined, and how to convert dates. Our Hijri date converter does the conversion for any day.
This guide explains how the calendar works. For religious rulings on when to start a month or fast, follow your local mosque, scholars or official religious authority.
Origins and year numbering
Years are counted from the Hijra, the migration of the Prophet Muhammad from Mecca to Medina in 622 CE. Year 1 AH (Anno Hegirae) began in July 622 CE. The calendar was formally introduced under the Caliph Umar around 17 years later.
In October 2026, the current year is 1448 AH, which began on 16 June 2026 according to Saudi Arabia’s Umm al-Qura calendar.
The 12 months
| No. | Month | Notes |
|---|---|---|
| 1 | Muharram | Sacred month; Islamic New Year on 1 Muharram, Ashura on the 10th |
| 2 | Safar | |
| 3 | Rabi’ al-Awwal | Mawlid observed by many on 12 Rabi’ al-Awwal |
| 4 | Rabi’ al-Thani (Rabi’ al-Akhir) | |
| 5 | Jumada al-Ula | |
| 6 | Jumada al-Akhirah | |
| 7 | Rajab | Sacred month |
| 8 | Sha’ban | |
| 9 | Ramadan | Month of fasting |
| 10 | Shawwal | Eid al-Fitr on 1 Shawwal |
| 11 | Dhu al-Qa’dah | Sacred month |
| 12 | Dhu al-Hijjah | Sacred month; Hajj, Day of Arafah on the 9th, Eid al-Adha on the 10th |
Each month has 29 or 30 days, and a Hijri day begins at sunset, not midnight. That is why the first night of Ramadan’s special prayers (tarawih) is the evening before the first day of fasting.
Why dates shift about 11 days a year
A lunar month (from one new moon to the next) averages about 29.53 days. Twelve of them make about 354.37 days, so a Hijri year has 354 or 355 days. The solar Gregorian year has 365 or 366. The difference of about 11 days means:
- Every Islamic date arrives roughly 11 days earlier in the Gregorian calendar each year.
- A full cycle through the seasons takes about 33 years, which is why 33 Hijri years ≈ 32 Gregorian years.
- Ramadan falls in winter for some years and in summer for others, which changes fasting hours substantially, especially at high latitudes.
Examples: Ramadan 1447 began around 18–19 February 2026. Ramadan 1448 is expected to begin around 8 February 2027, subject to sighting or the authority each country follows.
How the start of a month is determined
There are several approaches, and they explain why dates sometimes differ by a day between countries.
1. Local moon sighting
The month begins when the new crescent (hilal) is seen with the naked eye after sunset on the 29th day. If it isn’t seen, the month completes 30 days. Countries such as Morocco, Pakistan and others hold official sighting committees. Cloud cover or geography can delay the start by a day.
2. Umm al-Qura calendar (Saudi Arabia)
Saudi Arabia uses the Umm al-Qura calendar, a calculated calendar, for civil and administrative purposes. For the key religious months (Ramadan, Shawwal, Dhu al-Hijjah), the Saudi Supreme Court announces the start based on sighting reports, which can occasionally differ from the printed Umm al-Qura date. Many online converters, including ours, use Umm al-Qura data.
3. Global astronomical calculation
Türkiye’s Diyanet, and many Muslim communities in Europe and North America (for example those following the Fiqh Council of North America), use astronomical criteria to fix months in advance. This makes planning easier and gives a single date regardless of local weather.
4. Following another country
Some communities follow Saudi Arabia’s announcement, or that of their country of origin.
None of these is “the correct” Hijri date in a scientific sense; each is a convention with its own reasoning.
Converting Hijri and Gregorian dates
Quick estimates
- Gregorian year ≈ Hijri year × 32/33 + 622 e.g. 1448 × 32/33 + 622 ≈ 1,404.1 + 622 ≈ 2026
- Hijri year ≈ (Gregorian year − 622) × 33/32 e.g. (2026 − 622) × 33/32 ≈ 1447.9, i.e. 1447 for the first half of 2026 and 1448 from mid-June.
These only tell you the year approximately.
Exact conversion
For an exact date you need a calendar table, because month lengths vary. Converters based on Umm al-Qura produce consistent results; dates based on local sighting can differ by one day. When a date matters legally (for example, a Saudi document with a Hijri expiry date), use the converter of the issuing authority or Umm al-Qura.
Key dates in 1448 AH (estimated)
| Event | Hijri date | Expected Gregorian date |
|---|---|---|
| Islamic New Year | 1 Muharram 1448 | 16 June 2026 |
| Ashura | 10 Muharram 1448 | 25 June 2026 |
| Start of Ramadan | 1 Ramadan 1448 | around 8 February 2027 |
| Eid al-Fitr | 1 Shawwal 1448 | around 9–10 March 2027 |
| Eid al-Adha | 10 Dhu al-Hijjah 1448 | around mid-May 2027 |
Future dates are projections; official announcements may differ by a day.
Common mistakes
- Converting at midnight instead of sunset. An event on Thursday evening is already the next Hijri day.
- Assuming one global date. Allow for one-day differences between countries.
- Adding 354 days to get “one Hijri year later” without checking, because some years have 355 days.
- Confusing the Hijri lunar calendar with the Solar Hijri calendar used in Iran and Afghanistan, which is a solar calendar starting at the spring equinox.
Checklist
- Know which convention applies: Umm al-Qura, local sighting or calculated calendar.
- Remember the day starts at sunset.
- Use an exact converter for documents and planning.
- Expect religious dates to move about 11 days earlier each Gregorian year.
Related: see our guide to how prayer times are calculated and our zakat guide, which uses the Hijri year for the zakat cycle.