The weather and seasons
On Howrse, the seasons last one week. Autumn starts on the first day of each real month. As it lasts 1 week, on the 8th of the month Winter begins, on the 15th, Spring arrives, and on the 22nd Summer starts. Summer lasts until the end of the real month in progress, and then the cycle of seasons starts all over again the next month.
In-game seasons have an impact on the amount of grass in meadows. There is a lot of grass in fertile meadows during the Spring and Summer, but it gets scarce in winter.