The Dechert Calendar at a Glance

Year Published 1996
Days per Week 7
Days per Month 52-56
Months per Year 12
Base Year Length 668
Leap Days 1
Leap Day Position end of 2nd month (of 12)
Basic Intercalation Formula 4x668 + 6x669
Extended Intercalation Formula
(\ denotes integer division)
(Y-1)\2 + Y\10 - Y\100 + Y\500
Mean Length of Calendar Year 668.5920
Base Astronomical Year Mean Tropical
Accuracy 2300 years
Cycle of Perpetuity none
Mean LS of Beginning of Year 274.0
Year Count Start 0
Epoch (CE) 1999 Dec 31 20:42:25
Epoch (JD) 2451544.36279
12-Month Naming Convention Anglicized Roman Days
1st Month January 56
2nd Month February
52-53
3rd Month March 56
4th Month April 56
5th Month May 56
6th Month June 56
7th Month July 56
8th Month August 56
9th Month September 56
10th Month October 56
11th Month November 56
12th Month December 56
7-day Naming Convention English
1st Day Sunday
2nd Day Monday
3rd Day Tuesday
4th Day Wednesday
5th Day Thursday
6th Day Friday
7th Day Saturday

Notes:

  1. This is one of several Symmetric Gregorian Martian calendars, which generally have the following characteristics:

  2. Other types of 12-month calendars are:

Document Time Keeping on Mars
Alan Dechert
Calendar Calendar
Martian Time

Martian Time

Martian Time Survey

Martian Time Survey 2.2