On Saturday, December 8, 2018 at 12:41:12 PM UTC-7, Mike Collins wrote:

Kurt Vonnegut had a Martian calendar in 1959.

You should see the Martian calendar I came up with!

Since the lunar month and the tropical year are incommensurate, there are lunar
calendars - the Chinese and the Jewish - that have years with either 12 or 13
months.

I proposed a Martian calendar which alternated between 22 months and 23 months,
with usually four out of every seven years having 23 months.

http://www.quadibloc.com/science/cal0503.htm

In this way, a Martian year would be divided into months having the same length
as 1/12 of an Earth tropical year.

Handy for paycheques, paying one's rent, and reconing people's ages in Martian
twelvemonths rather than Martian years - thus lending itself to better
integration between the Martian economy and Martian law with their counterparts
on Earth.

John Savard