What Is the Missing 13th Month Called? Understanding Undecimber
Learn about the missing 13th month called Undecimber and its role in alternative calendar systems like the International Fixed Calendar.
Did We Ever Have 13 Months in a Year? Exploring Ancient and Modern Calendar Systems
Discover how ancient Egyptians and the International Fixed Calendar proposed 13-month years with consistent formats.
Was There Ever a 13-Month Calendar? Discover the International Fixed Calendar
Explore the history of the 13-month International Fixed Calendar used by Eastman Kodak and its unique design with 28-day months.