The Heinlein Calendar at a Glance

Notes:

1. Although Heinlein did not specify the lengths of the months, this calendar is classified as one of several Symmetric Double Gregorian Martian calendars, which generally have the following characteristics:

   • Divide the Martian year into 24 months of approximately equal in duration 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 fourth month.

   • Base the month names on the traditional Roman names, plus some additional naming scheme

2. Other types of 24-month calendars are:

   • Asymmetric Vernal Equinox Martian calendars

   • Symmetric Summer Solstice Martian calendars

   • Symmetric Vernal Equinox Martian calendars

	Excerpts from Red Planet Robert A. Heinlein
	Martian Time
	Martian Time Survey 2.2