Surah 10 : Ayah 5

هُوَ ٱلَّذِى جَعَلَ ٱلشَّمْسَ ضِيَآءً وَٱلْقَمَرَ نُورًا وَقَدَّرَهُۥ مَنَازِلَ لِتَعْلَمُوا۟ عَدَدَ ٱلسِّنِينَ وَٱلْحِسَابَ ۚ مَا خَلَقَ ٱللَّهُ ذَٰلِكَ إِلَّا بِٱلْحَقِّ ۚ يُفَصِّلُ ٱلْـَٔايَـٰتِ لِقَوْمٍ يَعْلَمُونَ

It is He Who made the sun a radiant light[7] and the moon a reflected light[8], and precisely determined its phases, so that you may know the number of years and account [of time][9]. Allah has not created all of this except for a true purpose[10]. He makes the signs clear for people who know.