The Allison Calendar at a Glance

Year Published 1998
Days per Week 7
Days per Month 28-31
Months per Year 22
Base Year Length 668
Leap Days 3
Leap Day Position end of 2nd month
Basic Intercalation Formula 4x668 + 1x671
Extended Intercalation Formula
(\ denotes integer division)		 3 * (Y\5)
Mean Length of Calendar Year 668.6
Base Astronomical Year Winter Solstice
Accuracy 238 years
Cycle of Perpetuity none
Mean LS of Beginning of Year 277.2
Year Count Start 0
Epoch (CE) 1873 Dec 29 12:02:23 UTC
Epoch (JD) 2405521.502
22-Month Naming Convention Anglicized Roman
+ additional arbitrary		 Days
1st Month January 31
2nd Month February 28-31
3rd Month Bradbury 31
4th Month Clarke 31
5th Month March 31
6th Month April 30
7th Month May 31
8th Month Beltaine 30
9th Month Adumah 30
10th Month Kepler 30
11th Month June 30
12th Month July 31
13th Month August 31
14th Month Darius 30
15th Month Sagan 31
16th Month Tsiolkovsky 30
17th Month September 30
18th Month October 31
19th Month November 30
20th Month Sirius 30
21st Month Hypatia 30
22nd Month December 31
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:

This is one of several 22-month calendars.

document Accurate analytic representations of solar time and seasons on Mars with applications to the Pathfinder/Surveyor missions
Michael Allison
document What is a "Year" (on Earth or Mars)?
Michael Allison
document Mars Prime Meridian
Michael Allison
document A Mars Proleptic Calendar and Sol-Date Timing Reference
Michael Allison
document A post-Pathfinder evaluation of aerocentric solar coordinates with improved timing recipes for Mars seasonal/diurnal climate studies
Michael Allison and Megan McEwan
document Telling Time on Mars
Michael Allison and Robert B. Schmunck
document Time on Mars
Michael Allison
Calendar Calendar
Martian Time

Martian Time

Martian Time Survey

Martian Time Survey 2.2