Yes, they used in the last century and documented the school names on it that is what I red about. The old version may be saved at The library in Istanbul, Library of the Archaeological Museum (Arkeoloji Müzesi Kütüphanesi), Sultanahmet).
Conversions tables for the first of the month in the Turkish-named Hejira calendar to the Gregorian calendar and first of the month of the fiscal calendar to Gregorian calendar can be found in:
Birken, Andreas: Die Zeitrechnnung Handbuch der turkishchen Philatelie. Teil I: Osmanisches Reich. Arbeitsgemeinschaft Osmanisches Reich/Turkei, 1995, 40 pp. ISBN 3-931114-00-7. Bilingual (German and English). Available from: James Bendon Ltd., P. O. Box 56484, 3307, Limassol, Cyprus. Contact info as of 11/99: E-mail: [email protected].