> What man would need to track the 28-days cycle of the moon?!?
A hunter of any gender who wants to know approximately when the animals migrate or give birth, would benefit.
Things that are easy enough for anyone to track and count:
day/night cycles
lunar cycles
annual summer /winter cycles
"four moons after the middle of winter" is therefor useful as it's possible to count, more easily so than "112 days after midwinter"