Earth rotates (spins) about itself from West towards East while it is
going around the Sun. So the The countries in the East see the Sun
first. The countries in the West see the Sun later.
As the Earth
moves towards East, the Sun seems to travel towards the west during day
time, and in the evening Sun goes below the horizon in the West
direction, at Sun set time.
We have the international date line
in the ocean is near Japan. SO Japan gets the sun light first before
other nations every day. The western most point in USA sees the Sun