No other Race within the Hollow has as much experience with seasonal living than Humanity. The Daemon are nomadic in nature, never settling a single planet especially if they find the conditions there uncomfortable. The Divine have long been a stellar-borne, ship-ridden race. Terrasque come from a tidal-locked planet, and never developed interstellar travel; they only ever experienced a single season.
It fell to Humans to craft the Calendar by which those within the Hollow track time.
The Hollow experiences 4 Seasons which will move through each Region though out a year. Regions will not experience the same seasonal conditions simultaneously; while one Region experiences the warmer Season of Xanos, the Region opposite the world will experience the colder Season of Melos. That said, Region conditions might either mitigate or agitate the conditions brought about by each season. Kingdom, a colder Region, may still experience a more temperate Xanos, or a harsher Melos.
Lucos, the temperate season of and growth.
Xanos, the hot season of maturity.
Ios, the temperate season harvest.
Melos, the cold season of retreat.
Each Season is broken up into 12 Weeks, each Week lasting 7 Days.