International Fixed Calendar. The international fixed calendar movement lost its steam, and by 1937, the international fixed calendar league closed its doors. The original international fixed calendar league was created in 1923 and ceased operations in 1937, but now we are back.
The international fixed calendar (also known as the international perpetual calendar, the cotsworth plan, the eastman plan, the 13 month calendar or the equal month calendar) is a. It is a logical and easy to transition to.