Calendar for the single year of 1775. The calendar is made from a disc of bronze, which has worn lettering on one side. On one side of the calendar is a table with the months in three letter abbreviations and a table with the numbers for the number of days. Around the edge of the table are inscriptions religious dates including Advent and Lent and the dates for Whit Sunday. The other side has a table relating to phases of the moon for each month. Around the table are dates including a term date, the King's birthday and information about sun and moon cycles.