Proleptic Julian calendar with year 0 corresponding to 1 BC, and "year −1" corresponding to 2 BC, so that in this system, Julian leap years have a number divisible by four. The determination of leap years in the proleptic Julian calendar (in either numbering) is distinct from the question of which years were historically considered leap years during the Roman era, due to the leap year error: Between 45 BC and AD 4, the leap day was somewhat unsystematic. Thus there is no simple way to find an equivalent in the proleptic Julian calendar of a date quoted using the Roman pre-Julian calendar
Pax Calendar to 48 hours or making Pax a month of 28 or 21 days to be added 18 times in 400 years. Pax Calendar The Pax calendar was invented by James A. Colligan, SJ in 1930 as a perennializing reform of the annualized Gregorian calendar. The common year is divided into 13 months of 28 days each, whose names are the same as in the Gregorian calendar, except that a month called "Columbus" occurs between November and December. The first day of every week, month and year would be Sunday. Unlike other perennial calendar reform proposals, such as the International Fixed