Virtually all civilization on Aestas, human or otherwise, track time via the movement of bodies in the night sky. The most important ones are the two moons, Atoros and Quarten. The night sky is occupied by two moons. The white moon Atoros is in a regular orbit, its predictable phases defining the calendar month in most civilizations. The red moon Quarten follows an elliptical orbit, and has no phases - the moon, whatever its true nature may be, emits a dull red glow from its surface and shows no visible phases. Many cultures mark the roughly sixty day orbit of Quarten as supernaturally significant, most especially its closest and farthest approaches. The following time units are universal among all civilizations on Aestas, as they can be measured without requiring calculation or mechanical implements. Lesser measures such as hours, minutes, and seconds are mostly similar to the usual units, though some individual cultures use different methods of reckoning time on a small scale.
1 Aestas Year = 420 Days = 12 Lunar Months = 7 Arcane Cycles
Day: The Aestan day is obviously defined as the time from dawn to dawn. As such it is the most basic and universal unit of time on Aestas. It is approximately twenty-four hours long, as Aestas has roughly the same rotation rate and axial tilt as Earth. Different cultures divide the day differently, though all recognize midnight, noon, and the midpoints between as significant times.
Lunar Month: Tracked by the phases of the moon Atoros, a month on Aestas is roughly thirty-five days long. A bewildering array of different subdivisions are used around Aestas, though both the Keller and Pershamon civilizations use the same division into five weeks of seven days each. In the southern hemisphere, the Uthman and Taohuan civilizations share the practice of four weeks of eight days each followed by a three day period of ritual significance. In both cases, it is standard to retain months of thirty-five days, based on the Atoros lunar calendar. The various minor civilizations of Aestas, including nonhuman ones, use their own calendar systems.
Lunar Year: Aestas orbits its primary star more slowly than Earth, resulting in a longer calendar year of four hundred and twenty days. Using the lunar cycles of Atoros, this neatly divides into twelve months, each thirty-five days long. The four seasons of the temperate zones each last roughly one hundred and five days, though whether time is actually divided this way tends to be a regional and cultural thing.
Arcane Cycle: The small red moon, called "Quarten" by the Keller, takes roughly sixty days to make a complete circuit from perigee to perigee, which it completes seven times each standard year. Most cultures mark the closest approach of this moon as a time of dread, as supposedly the veil between life and death are thinnest. Most magic practitioners (wizards, warlocks, and so forth) keep a close eye on this cycle, as their own abilities might measurably wax and wane as Quarten processes through its orbit. A few cultures use Quarten as the basis of their calendars, Yanosh being the most famous example.