Demo:
http://www.mediafire.com/?yvygcxbkrgd

Features:
-Changing Screen Tone (Day/Night)
-A switch that indicates when night occurs
-Lights for buildings, houses, etc.
-Customizable time interval

Description:
This system uses a set of three common events, variables, a switch, and modifications to transfer events to create a system that simulates day and night. It is completely customizable because it is an event system and, from what I've seen, doesn't cause lag. When you open the editor, be sure to look at every event, including the transfer events, because they are very important for the small stuff like removing the light graphic. You can do most things with this system that you could do with a scripted version although it requires more work. If there are any questions/comments, please post them and I'll answer as soon as possible.

Uses:
-Switch
To change from day to night for events like lights.
-Variables
These are used to record the current time. Without them, the parallel event will start over each time you enter a new map.
-Transfer Events
If you're using the light graphic, you have to include the Erase Picture command(s) or you'll have random lights in the middle of the screen.

Notes:
-I have tried making this system for XP, but I experienced trouble with the parallel event and it created a lot of lag. Therefore, I do not intend to make this system for XP.
-I made this event system a looooong time ago and there are probably ways to improve upon it, but this is what I have right now. If anyone is interested in an updated version, let me know!

Credit for the light tutorial and graphic:
Angelman

Very nice. I may look into converting it to xp some time

Valdred
Tech Administrator of Save-Point

Thank you! :3

At one point, someone else tried converting it to XP, as well, but they weren't successful. The differences in how parallel events work is the culprit, I believe, so there wasn't anything we could do about it. This was a while ago, though, so my memory might be fuzzy. :P