The Hollon Calendar at a Glance

Year Published 1998
Days per Week 6-7
Days per Month 27-28
Months per Year 24
Base Year Length 668
Leap Days 1
Leap Day Position end of year
Basic Intercalation Formula 668, 669 by observation
Extended Intercalation Formula
(\ denotes integer division)
N/A
Mean Length of Calendar Year 668.5906
Base Astronomical Year Vernal Equinox
Accuracy infinite
Cycle of Perpetuity 28 days
Mean LS of Beginning of Year 0.0
Year Count Start undefined
Epoch (CE) undefined
Epoch (JD) undefined
24-Month Naming Convention Alphabetical space historical Days
1st Month Aldrin 28
2nd Month undefined 28
3rd Month undefined 28
4th Month undefined 28
5th Month undefined 28
6th Month undefined 27
7th Month undefined 28
8th Month undefined 28
9th Month undefined 28
10th Month undefined 28
11th Month undefined 28
12th Month undefined 27
13th Month undefined 28
14th Month undefined 28
15th Month undefined 28
16th Month undefined 28
17th Month undefined 28
18th Month undefined 27
19th Month undefined 28
20th Month undefined 28
21st Month undefined 28
22nd Month undefined 28
23rd Month undefined 28
24th Month Zubrin 27-28
7-day Naming Convention English planetary
1st Day Sunday
2nd Day Phobosday
3rd Day Deimosday
4th Day Earthday
5th Day Venusday
6th Day Jupiterday
7th Day Saturnday

Notes:

  1. Each month begins on the first day of the week. The week at the end of each quarter contains only six days.

  2. The calendar is identical in structure to the Darian calendar, but was developed independently. Differences are:

  3. This is one of several Symmetric Vernal Equinox Martian calendars, which generally have the following characteristics:

  4. Other types of 24-month calendars are:

Document Rationale for the Martian Calendar's Structure
Bill Hollon
Calendar Calendar
Martian Time

Martian Time

Martian Time Survey

Martian Time Survey 2.2