The International Fixed Calendar - https://en.wikipedia.org/wiki/International_Fixed_Calendar https://en.wikipedia.org/wiki/International_Fixed_Calendar . > Th

The International Fixed Calendar - https://en.wikipedia.org/wiki/International_Fixed_Calendar https://en.wikipedia.org/wiki/International_Fixed_Calendar . > The calendar year has 13 months with 28 days each, divided into exactly 4 weeks (13 × 28 = 364). An extra day added as a holiday at the end of the year (December 29), sometimes called "Year Day", does not belong to any week and brings the total to 365 days. ... > International Fixed Calendar inserts the extra day in leap year as June 29 - between Saturday June 28 and Sunday Sol 1. Kodak used it for years. I recall that it helped with business operations because it was easier to compare costs and production between the months.