Hijri, Gregorian and Rumi Date Converter

How Does Cross-Calendar Date Conversion Work?

Converting Gregorian Dates to Hijri and Rumi

Enter the year, month, and day on the Gregorian card. The Hijri date (day, month name, year) and the Rumi (Ottoman) date appear immediately on the other cards. Conversion runs through a Julian Day Number bridge and uses the tabular Hijri algorithm.

Mapping Hijri and Rumi Dates Back to Today's Gregorian Calendar

Enter values into the Hijri or Rumi card to convert in the opposite direction. To convert a grandparent's birth date from the Turkish e-Devlet genealogy view, or a Rumi date from an Ottoman archive document, use that card. Select the Hijri month from the dropdown; the Rumi month works the same way.

What Are the Differences Between the Hijri, Gregorian, and Rumi Calendars?

Hijri Calendar (Lunar-Based Islamic Calendar)

The Hijri calendar starts with the Prophet Muhammad's migration from Mecca to Medina in 622 CE and follows the real lunar cycle. Each month is 29 or 30 days, so 12 months total 354 or 355 days. Because that is about 10.88 days shorter than the solar year, Hijri months arrive 10–11 days earlier in the Gregorian calendar each year, and the cycle resets every 33 years. Ramadan, Eid al-Adha, Laylat al-Qadr, and the holy nights are all set by this calendar.

Gregorian Calendar (Solar-Based Universal Calendar)

Introduced by Pope Gregory XIII in 1582, the Gregorian calendar is solar-based. Türkiye officially adopted it on 26 December 1925. A common year has 365 days and a leap year 366, with 1 January as new year's day. It is the global standard for civil time and international communication.

Rumi Calendar (Ottoman Fiscal System on a Julian Base)

The Rumi calendar served the Ottoman Empire's fiscal and administrative work. It is a solar calendar built on the Julian system: the year count starts from the Hijra, but month lengths follow the solar year. The new year falls on 1 March, and Rumi years lag Gregorian years by 584 from March to December and by 585 in January and February. It was retired on 1 March 1917 but is still the reference for Ottoman archive documents and genealogy research.

What Is This Date Converter Used For?

Finding Religious Days, Holy Nights, and Ramadan

Use the Hijri card to find the Gregorian date for events like Laylat al-Qadr, Mawlid, Eid al-Adha, and Ramadan. For example, entering 27 Ramadan 1447 immediately shows its Gregorian equivalent. Important: the tool uses an arithmetic algorithm, so it can differ by ±1–2 days from official dates set by lunar sighting. For religious obligations, follow the official calendar of your authority.

Reading e-Devlet Genealogy Records

In Türkiye's e-Devlet genealogy view, grandparents' birth dates often appear in Rumi or Hijri form. Convert them to Gregorian to find the real birth year and age. Enter the document date on the Rumi card and the tool returns both the Gregorian and Hijri equivalents. Example: an e-Devlet record showing Rumi 1 March 1308 corresponds to 13 March 1892 Gregorian.

Reading Ottoman Archive Documents and Old Title Deeds

Many Ottoman-era documents in state archives — title deeds, waqf records, census registers, and imperial decrees — are dated using the Rumi calendar. Historians, family researchers, and property historians can use this tool to convert Rumi dates to Gregorian. Some documents are dated in Hijri instead; both modes are available and always show the equivalents in the other two calendars at the same time.

Frequently Asked Questions

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