Description
The left-hand side is intended for the calculations in the Rumi calendar, with a small slot in the upper part marking the number of the days in each month of the Rumi calendar, which is corresponding the Julian calendar, and the larger slot below with a volvelle in the back, showcasing the dates of the month aligning with the corresponding names of the days of the week on the side.
The right-hand side of the lithography showcases the same information for the Hijri calendar, which differs from the Rumi calendar.
Added are additional charts for important dates for each calendar and quotations regarding the sun and moon, some of which are added in a manuscript in black ink. The middle panels give calculations for important times for the lunar calendar in the 12 months of the year.
Both calendars, Rumi and Hijri, were used parallelly in the Ottoman Empire.
The Rumi calendar, literally meaning “The Roman Calendar”, which follows solar days and is adjusted to the Julian calendar, was in use since 1677, but became official during the Tanzimat reforms, on March 13, 1840 and was used for fiscal years and also for imprints on books, magazines and documents. The difference between the modern Christian calendar and Rumi years is in general 584 years.
For religious matters the inhabitants of the Ottoman Empire still followed the traditional Hijri lunar calendar (also called the Islamic calendar) and exact calculations of the movement of the moon were important for prayers and holidays, which were held on different times of days and years.
The present paper instrument offered the user useful information for both of the calendars. The imprint on the lower right-hand side states, that it was printed for the first time and with the permission of the office for education by Al-Hac Halil.
Thought the centuries there were several attempts to make Ottoman perpetual calendars (or at least calendars for next few years), mostly in forms of long manuscript or lithographed scrolls, ruzname, which one could carry in a pocket or diagrams in forms of square charts or rondelles with or without volvelles.
We could not find any references to the present paper document in the literature nor any similar objects.
