How to control the time ?
It works like a tape recorder, you control the date with the buttons.
Everything is pretty simple, only the "Sync." checkbox needs some explaination:
If this box is checked, the animation speed is synchronized with the time set in the listbox above. This allows you to set the frames calculated to for instance to exactly one sideral day. As long as the checkbox is checked "Slower" and "Faster" reduce the number of frames per second and not the time span between two frames. Once you uncheck it and click "Slower", the time span between the frames gets smaller.
The geocentric and heliocenric view is independent of the location while the heliocentric view has a control for the distance.