Oh Allah, now I see.
"It is He Who made the sun to be a shining glory and the moon to be a light (of beauty), and measured out stages for it; that ye might know the number of years and the count (of time). Nowise did Allah create this but in truth and righteousness. (Thus) doth He explain His Signs in detail, for those who understand."
Al-Quran, Surah Yunus, Ayat 5 [10:5]