Publication: An Easter 'cheat sheet'

A medieval calendar preserved in AM 249 d fol. (Copenhagen, The Arnamagnæan Institute) contains an Easter Table. Easter Tables were used as "cheat sheets" allowing their users to determine the date of the Easter. The cheat sheet in AM 249 d fol. allows you to calculate dates of Easter for the years 1140-1671. 

I wrote a short piece about this manuscript for Manuscript of the Month series. You can read the original article here (on the official blog of the Arnamagnæan Institute).

An opening from AM 249 d fol. Photo: Katarzyna Anna Kapitan