Quran 25:62

وَهُوَ ٱلَّذِى جَعَلَ ٱلَّيۡلَ وَٱلنَّهَارَ خِلۡفَةً۬ لِّمَنۡ أَرَادَ أَن يَذَّڪَّرَ أَوۡ أَرَادَ شُڪُورً۬ا ٦٢

He is the One who designed the night and the day to alternate: a sufficient proof for those who wish to take heed, or to be appreciative.