As the earth rotates on its own axis every 24 hours the hemisphere facing the sun will experience summer while the other hemisphere will experience winter in addition the earth rotates around the sun every 365.25 days with an axis tilt of 23.5 degrees.This allows for the hemisphere tilting towards from the sun to experience daylight while the area of the earth tilting away from the sun to experience night while the area of the earth tilting towards the sun to experience summer
