Watermark: Anchor in circle. See Edward Heawood, Watermarks, Mainly of the 17th and 18th Centuries (Hilversum, 1950), nos. 1-8.Text and table rubricated; marginal corrections in hand of copyist; marginal notes in another hand.Possible 17th-cent. date based on table showing correspondence of Islamic years 990-1500 [i.e. 5 February 1582-16 November 2077] with Coptic years 1299-1794.Deals with the conversion of calendars in the Coptic and Islamic systems, making astronomical observations, and a very brief treatment of numerology. Text unidentified; copy defective (introduction missing), text begins with faṣl 1 and consists of 3 faṣls followed by 7 bābs and a khātimah. Colophon missing.