Unfortunately, Spartoi, vodyanoi, and elves don't have a unified calendar system between different subcultures. Gorgons, who don't care about the cycle of seasons, likewise would find it hard to track the time. Humans from the same cultures, or Hecatites of any culture, would be the only people who can easily tell the time gap between the Rise & Double Valence generations (the gap between Double Valence and Starquake is small enough that only Spartoi and vodyanoi would have trouble communicating the time gap between tribal groups, and within tribal groups they'd have no problem).