A lunary (from Latin lunarium), also called a selenodromion or moonbook, is a book of prognostication based on the position of the moon at any given time.
[3] There are examples in Greek, Latin, Coptic, Middle English and Old Nubian.
[3] The lunary was "by far the most popular and widely circulated prognostic genre" during the Middle Ages.
[6] Lunaries are similar to electionaries in that they were used for choosing (electing) astrological propitious dates for events.
[1] Lunaries were used for predicting and planning birth, business, death, illness, marriage, planting, phlebotomy and travel.