if you're a girl, it ends when you get married, (Which stinks, if you ask me.) and then if you're a boy, or a girl that doesn't want to get married, you have a certain time limit, but I forgot what it was.

Ditto what she said only I think the time limit is something like three years. I've ended the game (as a girl obviously) after three years. I also was married once and that happened in fall of Year 2. I hope that answers your question a little better.