PERPETUAL CALENDAR
This beautiful perpetual calendar is based on the Sunday letter. These letters applied by the astronomer, in charge of creating the Gregorian calendar, Christopher Clavius in 1582. It consists of applying a letter to the first seven days of the year, in such a way that the letter A corresponds to January 1, B to the second, C to January 3rd and so on until G which corresponds to January 7th. The Sunday letter for a specific year is the one that corresponds to the first Sunday of that year.
With this system and through some simple calculations we can find out the day of the week on which a specific date fell and during a period of one thousand two hundred years with complete accuracy.
It is provided with two sides: One is a partial reproduction of the “Planisferium Copernicanum”, and the other side is the reproduction of a compass rose and the profile effigies of Galileo Galilei and Newton.
It is made of bronze-plated metal and is accompanied by a small manual with its history and instructions for use.
On our blog you can read much more about calendars and how this perpetual calendar works.
Measures:
Height: 13 cm
Width: 9.5cm
thickness: 1.5cm
VAT INCLUDED
https://en.wikipedia.org/wiki/Perpetual_calendar
