Thanks ;) That was indeed one of the aim of the game. To let you play at your own pace. There is only one girl who has a 1 month deadline before being locked away though, Kumiko. Might want to focus on her first if you want to add her to your harem ;)
If you want her to not get married, then you'll have to increase her obedience and affection in one month indeed. If you don't care, you can just ignore her.
