Hallo Mahmood,

yes there is such a change over year. Angle between rotation axes of earth (line through the poles) and area formed by earth's trace moving arround sun in one year is not 90°. It's about 90°-23.5°=66.5° So, at winter and summer virtual position of sun in the sky differs drastically. When your postion on earth has a certain latitude 'b' then angle 'a' between perpendicular line on earth surface and highest position of sun at noon would be:

a = b + 23.5 x cos(2 x pi x d / 365)

When 'd' is number of day nominated to New Year, means d=0 for january 01 and d=183 july 01.
So, for Jordania (b=30°) at January 01 a=53.5° and for July 01 a=6.5°.

This formula is a quickshot by me. I don't know whether it's correct. Please test for yourself...

Bye,
Kai