Feast days of saints are listed in the church calendar that commences on September first and lists the lives of saints in monthly succession. The lives of saints were portrayed in manuscripts and reproduced in monthly calendar icons, to serve the needs of observance in worship. The earliest surviving such monthly calendar icons are to be found in Sinai.
This diptych depicts all the saints celebrated throughout the year, while on the top part of each panel we find Christ and the Mother of God, along with the major feasts of the Christian Church. Each day’s saints are portrayed in groups of three, interrupted by major feast images. The miniature work is of exceptional quality.
This monthly calendar is evidently associated with relevant manuscripts, and Constantinopolitan art in general.