Time in RimWorld passes as a series of ticks. On normal game speed, there are 60 such ticks to a real second; there are always 2,500 ticks to one in-game hour.
The game starts in the year 5500. The in-game clock is in 24-hour format with the hours displayed in military time from 0H to 23H.
Time proceeds as one would expect except that the four months are named "quadrums." They are named as portmanteaus of terrestrial months, suggesting seasonal associations: "Decembary," "Aprimay," "Jugust," and "Septober." Each individual quadrum is always 15 days, after which you proceed into the next quadrum.
As of Alpha 16 (December 20th, 2016), time of day is modeled on the planet view; local time of day corresponds to how the sunlight hits the planet.
As of Alpha 17 (May 24th, 2017), season names could no longer be consistently applied to the entire globe, necessitating that they be named as month-like "quadrums."
|In-Game Time||Ticks||Real Time|
|1 Hour||60 Min||2,500||41s|
|1 Day||24 Hours||60,000||16m 40s|
|1 Quadrum||15 Days||900,000||4h 10m 0s|
|1 Year||4 Quadrums||3,600,000||16h 40m0s|