2 Hours Love

A contractual relationship where the couple meets only for 2 hours a day. While the guy is reluctant but the girl insists that they meet between 4 to 6 PM only. Before 4 and after 6, they behave like strangers. There are a few other conditions stated in the agreement. If the guy breaks any of the rules, the girl will terminate the agreement and their relationship. How long can such a relationship last?