Recently, I learned that there’s an actual Martian calendar, known as the Darian Calendar. It was crafted by aerospace engineer Thomas Gangale in 1985, who named it after his son Darius. It was also adopted by the Mars Society in 1998 and will be the official calendar of Martian settlers (if and when permanent settlements are built on Mars someday).

It’s specially made for Mars, which has a very similar diurnal cycle to Earth – a day (or Sol) is 26 hours long. But since a year is almost twice as long, the calendar has 24 months, which are divided into blocks of 6 months each. Each month has 28 days, except the last in a block (which has 27). According to the description on Wikipedia, the calendar is structured as follows:

“The year is divided into 24 months. The first 5 months in each quarter have 28 sols, while the final month has 27 sols unless it is the final month of a leap year, when it contains the leap sol as its final sol. The calendar maintains a seven-sol week, but the week is restarted from its first sol at the start of each month. If a month has 27 sols, this causes the final sol of the week to be omitted.

“This is partly for tidiness and can also be rationalised as making the average length of the Martian week close to the average length of the Terrestrial week; 28 Earth days is very close to 27+1⁄4 Martian sols, whereas a month is an average length of 27+5⁄6 Martian sols. In the table, the sols of the week are Sol Solis, Sol Lunae, Sol Martis, Sol Mercurii, Sol Jovis, Sol Veneris, Sol Saturni.”

Well, guess what I decided to make? A calendar for Venus! Granted, this is a dating system that will only work if and when humans speed up the planet’s rotation to give it a 24 hour period (an essential aspect of terraforming Venus). Once that is done, the planet will need to have a calendar that can accommodate a 224.7 day year.

Doing the math, I found that a week of 5 days, a three-week month, 15 months, and a “leap year” every 10 years (where it’s actually three days shorter) would work. And the months and days all take their names from different cultures and the names they ascribed to the planet Venus or the associated fertility goddesses.

Here’s how it breaks down: The days of the week are Sol Khonsu, Sol Winalagalis, Sol Rosmerta, Sol Tohil, and Sol Inanna, the corresponding deities to Luna, Twi, Woden, Thor, and Freya – for whom the days of Monday to Friday are traditionally named.

Meanwhile, the 15 months are all named after fertility goddesses from various religions and cultures. Their names (in alphabetical order) are Anahita, Aphrodite, Atahensic, Attar, Barnumbirr, Chapska, Cliodhna, Denke, Kokopelli, Oshun, Quetzalcoatl, Śukra, Tioumoutiri, Wünelve, and Zohra.

In keeping with the naming conventions of the Formist Series, I have decided to stick with the adjective “Cytherean,” as opposed to “Venusian.” I feel it sounds better and does a better job of conveying the mythos behind the names of the Solar planets. Having said all that, here is how it will look!

Behold, the Cytherean Calendar (patent-pending!):