Armelin's calendar
Armelin's calendar was developed around 1887 by French astronomer Gustave Armelin, who developed a twelve-month calendar in which the year of 364 days was divided into four equal quarters of 91 days.
Armelin's calendar proposal was discussed chiefly under the auspices of the Société astronomique de France in 1887 and recently in the French Academy of Sciences.
The advantages of this simple system are evident. The months are nearly equal in length, and all have the same number of business days. Any given day of any month falls on the same day of the week each year. A mind of modest ability will learn in a few minutes the weekday with which each month invariably begins, and will be able to compute quickly the day of the week upon which any day of any month falls. Each stated holiday falls upon its invariable day of the week. Thanksgiving Day falls always on November 30.
A major disadvantage is for sabbatarians, who are obliged to worship every seventh day. Their holy day will occur on a different weekday every year.
Armelin's project received the first premium of the French Astronomical Society. The World Calendar, roughly identical, has been promoted by the World Calendar Association since 1930.[1]
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