وَهُوَ ٱلَّذِى جَعَلَ ٱلَّيْلَ وَٱلنَّهَارَ خِلْفَةً لِّمَنْ أَرَادَ أَن يَذَّكَّرَ أَوْ أَرَادَ شُكُورًا

And He it is Who made the night and the day to follow each other for him who desires to be mindful or desires to be thankful.