I already found the BP is in the base game content sorry my bad, Luis.
Hi , the day/night system i’m using from “Kleiner Baer” don’t use this variable. In fact uses a very advanced math expresions to determinate the rotation of the sun/lightsource, day counts and years count; even equator position to determinate the direction of the rotation sun. Is like a recreation of the rotation of the solar system. With this system you can even determinate the seasons.