In-game Clock and event triggers.

Highly advise against this unless you want to put yourself at risk of tying the clock speed to the framerate. If all you’re looking for is adding to a variable representing the overall time and then doing your calculation to get it into a 24-hour format, make a standard timer that works in realtime working first. To do that all you have to do is add to a variable in gamemode and make sure to multiply by Delta Time to avoid the clock speed changing based on the framerate. Then just make a separate variable to represent the time multiplier (in your case, 2.0) and just multiply using that variable before adding it to the time variable; that way you can use event triggers to change the multiplier variable whenever you want.