'Flat-earth', i wrote this to give you a smile, a couple of years ago i'd seen a wristwatch -i thought that is must have been made vor classic painters, not using a photoshot or better their own mind, but a sketch drawn outside (in the wild), its display showed a model of the time-dependent shaddow cast, using two overlaying layers which build the shaddow. It took a while and reading till i fiddling out how the time-setting to get a correct shaddow-cast will be done (hypothetical) by using a list on the internet. Hint: 'What may be possible done with building a watch' ^^