will there be different girls at night?
or does that youst mean they all go to sleep and we walk around the areas alone?
The entirety of the Day/Night system will likely not be implemented when first released. It is possible that there will eventually be new mobs at night and thus different groups to encounter during the day and night, but the current encounters will likely be the same during the day and night for now. Until it is actually added, there are a number of things up in the air. However, one potential dangerous change, and to emphasize that exploring while it is night is risky, will be the Caverns Salari being encountered in the Forest at night. There may also be enemies that are stronger during the night as well. So if either or both of those make it in for this initial implementation, early game players will learn quite quickly to stay in Town and/or sleep during the night and wait for daytime to arrive.
One primary reason for the Day/Night system will be to enable the passage of time and allow things like addictions to actually decrease given we have no system in place for measuring time and allowing such things to bleed off and wind down naturally. Another reason for the Day/Night system is to breathe more life into the world and allow some other things to happen, such as dreams or your dreams being invaded by certain individuals. There is that hidden Addiction to Sofia stat to remember after all.
A few other plans for the Day/Night system would be to allow the player to visit the bar at night should they wish to do so. Then there is also the chance of certain individuals actually visiting you at night in addition to those who may invade your dreams. Trisha, Vili, and Shizu have been put forth as likely candidates for either invading your dreams or sneaking into your room at night. Given the latter does essentially start stalking the player, it would not be surprising if Shizu is one of the first to have a night visit scene added.
However, as I previously stated, until it is actually in the process of being implemented and it is closer to being released, there is a fair amount that could go into that particular system but will not be known for sure until it is actually added. Deliberations on whether or not to go with clear time phases for being either Day or Night or ticks of time where there would essentially be hours of each were still going on yesterday, so it's still somewhat in the planning stages as well.
I know this is a fair amount of maybes and possibilities, but I do hope that this is a satisfactory amount of information for now,
decker2.