This Java applet computes the position of the sun in the sky (zenith, azimuth) at any instant of the day as well as the hours for sunset and sunrise. Customer may change day and latitude. Time is solar time. Dragging the mouse on the curve provides the angular position of the sun (azimuth, elevation), which is displayed below. The night hours are presented in grey.

The equations used are those described in the European Solar Radiation Atlas (see the ESRA handbook, volume 2).

Free software is available.