The golden numbers are the numbers assigned to each year in sequence to indicate its position in a 19-year Metonic cycle. They are used in the calculation of Easter and also in the Runic calendar. This term was not used in classical times: its first documented use is in the computistic poem Massa Compoti by Alexander de Villa Dei in 1200. A later scribe added it to tables originally composed by Abbo of Fleury in 988. The Metonic cycle or Enneadecaeteris in astronomy and calendar studies is a particular approximate common multiple of the tropical year and the synodic month. ... Computus (Latin for computation) is the calculation of the date of Easter in the Christian calendar. ... The Runic calendar (or Rune staff) appears to have been a medieval Swedish invention, whereas clog almanacs appear in several European countries. ... Abbo of Fleury (in Latin Abbo Floriacensis), also known as Abbon or Saint Abbo (c. ...

The golden number of any Julian or Gregorian calendar year can be calculated as the year number modulo 19, plus 1. The Julian calendar was introduced in 46 BC by Julius Caesar and took force in 45 BC (709 ab urbe condita). ... Inscription on the tomb of Pope Gregory XIII celebrating the introduction of the Gregorian Calendar The Gregorian calendar is the calendar that is used nearly everywhere in the world. ... The word modulo is the Latin ablative of modulus. ...

It has nothing to do with the golden ratio. The golden ratio, also known as the mean and extreme ratio, golden proportion, golden mean, golden section, golden number, divine proportion or sectio divina, is an irrational number, approximately 1. ...