Leap Year
The Leap Year Day is inserted in order to keep the Calendar Year correspondent to the Tropical Year. Without the Leap Year Day, the Calendar Year would drift relative to the Seasons, eventually leading February to Summer in the Northern Hemisphere.
In the case with the Gregorian Calendar, much of its irregularity lies in the counting of the Leap Year Day on February 29th, as a Calendar Day, as opposed to counting it off the Calendar, as has been the custom in other systems.
Were the Leap Year Day to fall between February 28th and March 1st without a Month or Date assigned to it, then the Gregorian Calendar Year would repeat the pattern of weekdays, months and dates every 7 Years, instead of every 400 Years.
The Different Measures of the Year
365.242 189 670 Days per Tropical Year
365.2425 Gregorian Calendar Days per Year
365 Reform Calendar Days per Year
In order for the 365- 360- and 260-Day Reform Calendars to work in regular progressions of their respective cycles and sub-cycles, the Leap Year Day is acknowledged off of each of these Calendars.
The Leap Year Day is counted on the Lunar Calendar and the Chronological Count of Days.
There are two schemes by which the Leap Year Day can be scheduled for periodic insertion.
1) The Gregorian periodicity – 365.2425
1 Leap Year Day every 4 Years
unless the Year is divisible by 100
except for Years also divisible by 400
Leap Year Days every 4 and 400 Years.
No Leap Year Days on Century Years, unless it is also divisible by 400.
2) The 13-Moon periodicity – 365.2422031
1 Leap Year Day inserted every 1508th Day.
This can be scheduled according to the 260-Calendar’s measures of 13-Days, as 13 x 116 = 1508
The 365- 360- and 260-Day Calendars would best be served with the schedule most approximate to the Tropical Year.
