No responsibility is taken for the accuracy of these calculations.
The longitude and latitude of a large number of world cities can be
found on Infoplease.com.
All formulae are taken from the
RADIANCE
visualisation package
with kind permission from Lawrence Berkeley National Laboratory.
There is a very nice web-based shareware program called
Sun Angle Calculator
which does everything this calculator does and a lot more.
Times of sun rise and sun set do not take account of atmospheric refraction and
relative elevation. Times shown are simply when the sun's altitude
is 0°. In reality, the sun is only hidden when it is about 0.84°
below the geometric horizon. This is due to the atmospheric refraction
and the apparent radius of the sun which is 0.27°.