Calendar

The RimWorld calendar is much simplified compared to any "real world" calendars which players are used to.

From the game...

"The year is divided into 4 quadrums* of 15 days each. Quadrums are the same everywhere, while seasons are different in different places."

What this means is that while "Summer" and "Winter" are opposite depending whether one is north/south of the equator, and practically speaking if you are anywhere near the equator you have two "hot" seasons and two "not-quite-so-hot" seasons, the names of these 4 quadrums* are the same for everyone anywhere on the map.

It's also important to remember that 1 in-game "year" is only 60 days (4 quadrums of 15 days each). So, if something "spoils in 1 year", you have 60 in-game days, not 365.

The names of these 4 quadrums are:

• Aprimay
• Jugust
• Septober
• Decembary

Mouse-hovering over the in-game date (lower right-hand corner) will tell you what "local seasons" these represent for the settlement currently viewed. Note that if you have settlements on both sides of the equator, these seasons might be different, but the quadrum names will stay the same everywhere.

In any scenario, the starting year is 5,500, and the starting quadrum is Aprimay (which equates to "Autumn" if you are located in the southern hemisphere, or "Spring" if you are located in the northern).

(* The word "quadrum" is from the Latin for a 4-sided shape (square/rectangle), so here something of 4 sides returning back where it started; think "quarters" if you prefer.)

"60 day" years?

4 quadrums of 15 days each is a 60 day "year" - pretty short compared to the one we are used to. If you prefer, you can think of each in-game "day" as representing a little less than a week's worth of progress, 6 real-life days for each in-game calendar day, to be precise, for your 360 day year.

• See also: Lore