SUMMARY
9) The Marian Calendar in One Page

Mars has an almost Earth-length day but a year nearly twice as long.

That breaks several useful relationships in the Earth calendar.

Marian's answer is to separate the jobs.

Detailed figure description

A wide annual overview shows four quarter bands across twelve Marian months and twenty-four paired minths. Beneath, two small weekly grids contrast a normal 56-sol month with a shortened 55-sol month. The image emphasizes 12 annual month positions, 24 shorter operating minths, 668 or 669 physical sols per year, and the optional final Sunsol in leap years.

Editorial note: this is a descriptive summary, not an independently verified transcription of every diagram label. Refer to the surrounding text and the Marian technical specification for authoritative numeric details where applicable.

1 sol
The Martian civil day.

7 weekday positions
The familiar short recurring rhythm.

1 minth = 27–28 sols
About four weeks. The short operating cadence.

1 month = 2 minths = 55–56 sols
Twelve months divide the Martian year into twelve recognisable annual positions.

1 Sixth = 2 months
Six medium-range periods across the year.

1 quarter = 3 months
Four large annual divisions.

The common-year rhythm is:

56 – 56 – 55 | 56 – 56 – 55 | 56 – 56 – 55 | 56 – 56 – 55

giving:

668 sols

A leap year adds one final Sunsol to Month 12:

669 sols

The rule is:

Odd years leap. Tens leap. Hundreds do not.

The regular civil year is anchored to Mars at:

Ls = 15°

The idea underneath everything else is simple:

Minths provide cadence. Months provide annual orientation. Sixths provide a middle distance. Quarters divide the year.

The year belongs to Mars.