Lightmaps for night and day

Hello, i have a question about lightmaps, day and night, i don't have a night/day cycle, its just night or day, and all i do is to change the directional light intensity and turning off lens flare when is day, and i also change the texture for the skybox , so i want to know if i should use two different lightmaps for my levels, one for the night and one for the day, or if i can just turn off the lightmaps with a script on the day, i really don't know how to proceed with lightmaps for day and night, any help would be appreciated.