I've been concerned about it when they first announced it but then they said that a day in the game is actually 24 hours. That's 312 hours you start out with. I've never played an FF game that long in a single file (well except possibly FFVII, but I have no way of telling since that clock stops at 99:99:59 ) I know there will be some mechanic where you can gain and lose time, so we'll see how much time that shaves off.