Starcraft 2, like so many modern games in this age of modding, has a really robust level editor that's going to extend the lifespan of the game for years. You can edit almost anything about any of the game's many units buildings and maps, and make the game however you want it to be. This video will show you how to create a day and night cycle using the level editor that will make your games feel much more real. The creator included a download for a trigger library, but does not explain how to use them. You can also download the finished map from the video here.