Much strategic gameplay in the Kingdom revolves around Stat Days. When the moons are in certain phases, gains for a particular stat are increased. If Grimace is full, Muscle gains are increased. If Ronald is full, Mysticality gains are increased. If both moons look exactly the same, Moxie gains are increased. See moons for exact details. The moons have a 16 day cycle, out of which there are 2 Muscle Stat Days, 2 Mysticality Stat Days, and 2 Moxie days.
This moon cycle allows players to maximimize stat gain for a particular stat through careful gameplay. If a player is attempting to maximize, say, Muscle, they could special Muscle stat gaining things on days where Grimace is full. These things might include: using large stat items like Gourd potions or the chest of the Bonerdagon, selecting which food or booze items they consume, or donating at The Hall of the Legends of the Times of Old.