10- YÛNUS Jonah Revealed at Makkah/
5. It is He Who made the sun emit illumination and the moon derive its light from it (and reflect it to the earth). He determined the divisions of the ecliptic for the moon to occupy them on successive days and present its phases according to the extent of its illumination. This helps you to know the number of the years and reckon the time occupied by the sun in its apparent passage through the zodiac and the period of the earth’s revolution round the sun forming a natural unit of time, so that you may be able to compute time and determine it by calculation. Never did Allâh create this and bring it about but (for a serious end) with the truth. Thus Allâh expounds His signs and renders His words readily understood by those who know.