The earth rotates from west to east. The sun does not move around the earth in 30 minutes. The sun is seen in a different part of the sky, but this is due to the rotation of the Earth. The intensity of light and heat changes as the Earth rotates.
The speed of the sun changes the angle of the sky in 30 minutes, it is always moving from east to west, so in 30 minutes it will move further west, no matter what time you experiment.
