365.25 is a ratio- the number of rotations of the earth per revolution. In a real sense, it comes from our solar system. If you shy away from it, any given poi

365.25 is a ratio- the number of rotations of the earth per revolution. In a real sense, it comes from our solar system. If you shy away from it, any given point in your year's calendar will drift in terms of seasons. You see this in the around 354 day Hijri calendar, for instance. (Edited: removed claim 365.25 is unitless. The unit is rotations/revolution)