Time is measured differently in Anacreon than in the real world.
A “watch” is a real-time minute. It corresponds to six hours “in-game”.
A “period” is a real-time hour. It corresponds to 15 days “in-game”.
A “cycle” is a real-time day. It corresponds to a year “in-game”. The current in-game cycle is listed at the top center of the screen; new games start at cycle 4021, so you can tell how many real-time days that a game has been running by subtracting 4021 from the current cycle.