I found what I believe to be a bug in this game. I started the game with one of the villagers a parent, one with a baby. However, as I kept playing, the time left with the baby would remain on 246 minutes, even after an hour of playing on normal.

This only happened with the villagers who started out a parent with a baby. Having a baby after you have started the game works normal with time.

Edit: I run Windows XP.