Select position and date, and then move your mouse over the diagram to select the time of the day.
(Don't have a mouse? Move the yellow slider with your finger ...)
This is a nice tool for planning outdoor photography trips ... especially if you shift the map to satellite view. The zoom level of the map is increased, so you can really go into details.
Height is measured relative to the center of the sun disc.
Take also a look at 'Den gyldne time' (though it's still in danish).
