Every 7 or 6 years for a leap week 12 month calendar, it would be four times longer for a leap month, and the formula is a bit too complex for people to do in their heads, but we all refer to computer calendars anyway
A 364 day calendar with 13 even months, or 12 months alternating between 35 and 28 days or whatever would also let you use the same calendar every year (as opposed to my tea towel that has a calendar that is only useful in leap years that start on a Tuesday — the last was 2008 when it was bought, next is 2036)
Though it would be too expensive to change the calendar, and a 364 + leap weeks calendar doesn’t track the seasons as well as 365 + leap day calendar, I really like the symmetry 454 calendar
Every 7 or 6 years for a leap week 12 month calendar, it would be four times longer for a leap month, and the formula is a bit too complex for people to do in their heads, but we all refer to computer calendars anyway
A 364 day calendar with 13 even months, or 12 months alternating between 35 and 28 days or whatever would also let you use the same calendar every year (as opposed to my tea towel that has a calendar that is only useful in leap years that start on a Tuesday — the last was 2008 when it was bought, next is 2036)
Though it would be too expensive to change the calendar, and a 364 + leap weeks calendar doesn’t track the seasons as well as 365 + leap day calendar, I really like the symmetry 454 calendar