Ottoman Fiscal Calendar Converter

The Ottoman fiscal calendar, also called the Rumi calendar, was a Julian-based solar calendar used by the Ottoman Empire primarily for administrative, tax, and financial record-keeping. It was introduced in the mid-19th century and remained in use until the early Turkish Republic period (around 1926). Its year began on 1 March and it ran approximately 13 days behind the Gregorian calendar.

The Ottoman fiscal year starts on 1 March, so it straddles two Gregorian years. For example, Ottoman fiscal year 1316 began on 1 March 1900 (Gregorian) and ended on 28 February 1901. Because the calendar is Julian-based, its dates lag behind Gregorian dates by 13 days during the 20th century.

The Ottoman fiscal calendar is based on the Julian calendar, which does not apply the Gregorian calendar's century-year leap year correction. This causes a gradually increasing offset: 10 days in the 16th century, 11 in the 17th, 12 in the 18th, and 13 days by the 20th century.

The Ottoman fiscal calendar uses Turkish-adapted names corresponding to Julian months starting from March: Mart, Nisan, Mayıs, Haziran, Temmuz, Ağustos, Eylül, Ekim, Kasım, Aralık, Ocak, and Şubat. The year begins with Mart (March) and ends with Şubat (February).

The Ottoman fiscal calendar was formally adopted around 1840 and was used until 1926, when the newly founded Republic of Turkey fully transitioned to the Gregorian calendar. It was primarily used for government, tax, and military records during this period.

No. The Ottoman fiscal calendar is a solar Julian-based calendar, while the Islamic Hijri calendar is a purely lunar calendar. The Ottoman Empire used both: the Hijri calendar for religious purposes and the fiscal (Rumi) calendar for administrative and financial matters, which aligned better with agricultural seasons.

To convert an Ottoman fiscal date to Gregorian, first convert it to the Julian calendar by mapping the Ottoman month to the corresponding Julian month (Ottoman year 1 = Julian year starting March 1840). Then add the appropriate correction (13 days for most 20th-century dates) to get the Gregorian equivalent. This tool performs that calculation automatically.

The 1917 conversion table, referenced in historical sources including Wikipedia, provides a direct lookup between Ottoman fiscal calendar months and their Gregorian and Hijri equivalents for that specific year. It is frequently used by historians and archivists working with late Ottoman documents, particularly military and administrative records from World War I.