The Strom Calendar at a Glance

Year Published	1998
Days per Week	7
Days per Month	55-56
Months per Year	12
Base Year Length	668
Leap Days	1
Leap Day Position	end of 2nd month (of 12)
Basic Intercalation Formula	undefined
Extended Intercalation Formula (\ denotes integer division)	undefined
Mean Length of Calendar Year	undefined
Base Astronomical Year	Option 1: Anomalistic Option 2: Vernal Equinox
Accuracy	undefined
Cycle of Perpetuity	undefined
Mean L_S of Beginning of Year	Option 1: 70.8 Option 2: 0.0
Year Count Start	undefined
Epoch (CE)	2012 Jan 1
Epoch (JD)	2455928

Notes:

Option 1 is one of several Symmetric Gregorian Martian calendars, which generally have the following characteristics:
- Divide the Martian year into 12 months, symmetrically stretched to encompass the longer Martian year.
- Retain the seven-day week.
- Begin the year near the Winter solstice
- Place the leap day(s) in the second month.
- Base the month names on the traditional Roman names
Option 2 is a Symmetric Zodiacal Martian calendar, which is defined as generally having the following characteristics:
- Divide the Martian year into 12 months of approximately equal duration.
- Retain the seven-day week.
- Begin the year on the vernal equinox
- Place the leap day(s) at the end of the year.
- Base the month names on the zodiacal constellations
Other types of 12-month calendars are:
- Asymmetric Gregorian Martian calendars
- Asymmetric Zodiacal Martian calendars

	Martian Timekeeping Anders Ström
	Option 1
	Option 2
	Martian Time
	Martian Time Survey 2.2