This beautiful perpetual calendar is based on the dominical letter. These letters applied by the astronomer in charge of performing the Gregorian calendar, Christopher Clavius in 1582. It consists of applying a letter to the first seven days of the year, so that the letter A corresponds to January 1, B to 2nd C to January 3 and so on until the G correspopnde to January 7. The dominical letter for a particular year is that corresponding to the first Sunday of that year.
With this system and by simple calculations we can find out the day it went down a specific date and for a period of 1200 years with accuracy
It is provided with two faces: One is a partial reproduction of the "Planisferium Copernicanum" and the other side is playing a wind rose and the effigies of Galileo Galilei profile and Newton.
It is made of brass plated metal and is accompanied by a small booklet with its history and usage instructions.
In our blog you can read more about the calendars and the operation of this perpetual calendar.
Height: 13 cm
width: 9.5 cm
Thickness: 1.5 cm
1 opinion(s) "Millenary Perpetual calendar"
See more details in the video below that we offer.