Question

How change sun to day

Answer 1

Rotation of earth causes day and night
By d way watch video related this for better understanding

Answer 2

Earth spins on its on axis.So it appears as the Sun is moving across the sky.But there is another effect at work that makes Sun's apparent path different each day. The earth is also revolving around the Sun.so each Day of the year,The earth is at a different point in it,s orbit.