What is the Hijri calendar?

The Hijri (AH) calendar is the Islamic lunar calendar. It has 12 months based on the lunar cycle, giving a year of 354 or 355 days. Year 1 AH corresponds to 622 CE, the year of the Prophet Muhammad's migration from Mecca to Medina.

Why do Islamic holidays shift each year on the Gregorian calendar?

Because a Hijri year is about 11 days shorter than a Gregorian year, the same Hijri date falls about 11 days earlier in the Gregorian calendar each year. Over 33 years, Islamic dates cycle through all Gregorian seasons.

What algorithm is used for conversion?

This tool uses the Kuwaiti algorithm (tabular Islamic calendar), which calculates the Julian Day Number (JDN) as an intermediate value. The tabular calendar approximates the observational calendar and is the standard for civil and computational use.

Is this calendar the same as the one used in Saudi Arabia?

Saudi Arabia officially uses the Umm al-Qura calendar, which is observational (based on actual moon sighting) and may differ by one or two days from the tabular Kuwaiti algorithm used here. The tabular calendar is widely accepted for international use.

What are the 12 Hijri months?

Muharram, Safar, Rabi al-Awwal, Rabi al-Thani, Jumada al-Awwal, Jumada al-Thani, Rajab, Sha'ban, Ramadan, Shawwal, Dhu al-Qi'dah, Dhu al-Hijjah.

When does Ramadan start?

Ramadan is the 9th month of the Hijri calendar. Its Gregorian start date shifts approximately 11 days earlier each year. Use this tool to look up the approximate Gregorian dates for the current year.

Islamic Hijri Date Converter

Convert any date between the Gregorian civil calendar and the Islamic Hijri (AH) lunar calendar, in either direction.

Enter a Date to Convert

Gregorian Year

Month

Day

Conversion Result

Enter a date and click Convert

Important Islamic Dates —

Occasion	Hijri Date	Approximate Gregorian Date

* Dates are based on the tabular calendar. Actual observance may vary by one or two days depending on moon sighting in each country.

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Summary

The Islamic Hijri calendar is a purely lunar calendar of 12 months, each beginning with the new moon. A Hijri year is 354 or 355 days long, about 11 days shorter than the Gregorian solar year. The calendar starts from the year of the Prophet Muhammad's migration (Hijra) from Mecca to Medina, corresponding to 622 CE. Because the two calendars drift apart each year, converting between them requires careful arithmetic. This tool uses the Kuwaiti algorithm (tabular Islamic calendar) with the Julian Day Number as an intermediate step for accurate, bidirectional conversion.

How it works

Select the direction: Gregorian to Hijri, or Hijri to Gregorian.
Enter the year, month, and day in the input panel.
Click "Convert Date" to perform the conversion.
The result panel displays the converted date, Hijri month name, and the Julian Day Number used internally.
An Islamic dates reference table for the current Hijri year is shown below the converter.

Use cases

Find the Hijri equivalent of a Gregorian birthday or anniversary.
Determine the Gregorian date of Ramadan, Eid al-Fitr, or Eid al-Adha.
Convert historical Islamic dates for academic or genealogy research.
Plan events around the Islamic lunar calendar.
Verify dates in Islamic documents or inscriptions.

Frequently Asked Questions

Last updated: 2026-05-29 · Reviewed by Nham Vu