Luqman 31:29 الم تر ان الله يولج الليل في النهار ويولج النهار في الليل وسخر الشمس والقمر كل يجري الى اجل مسمى وان الله بما تعملون خبير ٢٩

The Might and Power of Allah Allah tells us that He

يُولِجُ الَّيْلَ فِى النَّهَارِ

(merges the night into the day,) meaning, He takes from the night and adds to the day, so that the day becomes longer and the night shorter, which is what happens in summer when the days are longest; then the day start