Hijri / Gregorian / Rumi Calendar Converter
Convert dates between Gregorian, Hijri and Rumi calendars. Uses the arithmetic Hijri calendar algorithm.
Miladi Takvim
Gregoryen Takvimi — Güneş Takvimi
GÜN
YIL
AY
29 Nisan 2026
Hicri Takvim
التقويم الهجري — Kamerî (Ay) Takvimi
GÜN
YIL
AY
12 Zilkâde 1447
Rumi Takvim
Mali (Osmanlı) Takvimi — Julyen Takvimi
GÜN
YIL
AY
16 Nisan 1442
* Hicri hesaplamalar cetvele dayalıdır (tabular); gerçek ay gözleminden 1–2 gün farklılık gösterebilir.
* Rumi takvim, Julyen takvimine dayalıdır ve Miladi takvimden 13 gün geridedir. Yıl başlangıcı Mart ayıdır.
Three Calendar Systems of Turkish History
For those researching Ottoman archives, querying religious dates, or comparing dates in old documents, converting between three different calendars is a necessity. The Gregorian, Hijri (Islamic) and Rumi (Ottoman) calendars operate with different starting points and year lengths. This tool enables instant conversion between all three systems.
This calculator uses the arithmetic (tabular) Hijri calendar algorithm. The actual Hijri calendar is determined by moon sighting; therefore religious dates may differ from the official Diyanet calendar by 1–2 days. The Rumi calendar calculation is based on the Julian calendar.
How to Use
Gregorian → Hijri & Rumi Conversion
Select the "Gregorian → Hijri & Rumi" tab, enter the year, month and day, then click "Convert". The Hijri and Rumi equivalents of the entered Gregorian date are shown instantly.
Hijri → Gregorian & Rumi Conversion
Select the "Hijri → Gregorian & Rumi" tab and enter the Hijri year, month and day. You can select the month name from the list. The Gregorian and Rumi equivalents are then shown as the result.
2026 Sample Date Conversions
| Gregorian | Hijri | Rumi |
|---|---|---|
| 1 January 2026 | 10 Rajab 1447 | 19 Kanunusani 1441 |
| 18 February 2026 | 29 Sha'ban 1447 | 5 February 1441 |
| 19 March 2026 | 28 Ramadan 1447 | 6 March 1441 |
| 29 October 2026 | 17 Rabi' al-Awwal 1448 | 16 Tesrinievvel 1442 |
* These are arithmetic algorithm results; use the official Diyanet calendar for religious dates.
Three Calendar Systems
Gregorian Calendar
The internationally used calendar system worldwide. Turkey switched to the Gregorian calendar on 26 December 1925. It is based on the solar year; a year is 365 days, or 366 in leap years.
Hijri Calendar (Islamic)
The Islamic calendar based on the lunar year. It takes the year 622 CE — when the Prophet Muhammad migrated from Mecca to Medina — as its starting point. A year is 354 or 355 days, shifting ~11 days earlier in the Gregorian calendar each year. Religious days such as Ramadan and Eid al-Adha are determined by this calendar.
Rumi Calendar (Ottoman)
The solar calendar used by the Ottoman Empire for financial and administrative matters. Based on the Julian calendar, it counts years from the Hijri migration but advances on a solar year basis. The Rumi year is 584 years behind the Gregorian year. The new year begins on 1 March. It was abolished on 1 March 1917.
How to Interpret Results
Conversion results are the equivalent of the same physical day in three different calendar systems. To convert a Rumi date you see in an Ottoman archive document to Gregorian, do not use the "Hijri → Gregorian" mode — enter directly in the Rumi field (Rumi → Gregorian mode).
Tips for Accurate Conversion
- Select Hijri month names from the list for accurate input; spelling variations may cause errors.
- For religious holidays and Mawlid dates, use the calendar published by the Diyanet (Presidency of Religious Affairs); calculations may deviate by 1–2 days.
- The Rumi calendar new year is 1 March; for January–February the Rumi year is 585 years behind the Gregorian year (584 years behind for March–December).
- Some dates in Ottoman documents may be given in the Hijri calendar rather than Rumi; pay attention to the context of the document.