I don’t want to “rain” on yours or anyone else’s parade. I am assuming from a coding standpoint this would be a large lift and this is why…
Currently the game runs off of a central clock which doesn’t cause any problems right now because there is no distinction between night and day. Everyone gets their events refreshed at the exact same time regardless of your time zone. If they were to implement night and day they would have to switch large blocks of time zones to different clocks in order to have “day” time in the park make any sense to someone while it is day time in their time zone same thing for night.
They could get around this by having day and night not be tied to reality and have it be more frequent like every 3 hours have the game switch from night to day and three hours later switch back so a 6 hour cycle this would give it 4 cycles a day and would be easily repeatable on a 24 hour cycle. It would be disconnected from night and day in real time but would allow for it to be centralized from a game clock perspective. But they would have to change a lot of graphics in the game since once you start putting point light sources in a night time environment (lights) you will have a ton of shadows to render from all sorts of different angles.
Don’t get me wrong I would love to see day, night, and weather added to the game to add another level of realism to it, it’s just highly unlikely from a resource perspective is my guess.