As applied to medieval manuscripts, a list of the principal feast days of the Church and the commemorative feasts of the saints throughout the liturgical year. It was an essential part of books used to celebrate Mass (the MISSAL, Pontifical and Benedictional) and the Divine Office (the PSALTER and BREVIARY), as well as of books of prayers used for private devotion (e.g. BOOK OF HOURS). Major Church feasts (e.g. Christmas and Easter), the commemorative days of the Apostles and other major saints or the names of saints particularly important in the diocese for which the book was made might be highlighted by being written in red, gold or blue. The text usually begins with an embellished KL (for Kalends, the Latin name for the first day of the month); the days of the week are indicated by lower-case letters a–g, accompanied by abbreviations of Ides and Nones. Golden numbers (i–xix) might also appear in the left column for calculating the date of the Paschal moon. Normally the text for such a calendar, with a line allocated to each day, occupied the recto and verso of 12 folios.

• calendars
  • Astrological and astronomical manuscripts, §1: Zodiacal and constellational imagery
  • Book of Hours, §2: Decoration
  • Industrial scenes, §1: Introduction
  • Observatory
  • Observatory, §1: Calendar observatories
  • Psalter
  • Aztec
    • Mesoamerica, Pre-Columbian, §IV, 4(ii)(b): Post-Classic monumental stone sculpture: Central Highlands
    • Mesoamerica, Pre-Columbian, §VI, 3: Manuscripts: Regional traditions
    • Mesoamerica, Pre-Columbian, §X, 1: Exploration and documentation
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    • Menologion of Basil II
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  • India, Republic of
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  • Mixtec
    • Mesoamerica, Pre-Columbian, §IX, 5(ii): Metalwork: Central and Southern Highlands