Use Stellarium (software) to Aim Solar Cookers.

Solar cookers usually need to be aimed "ahead of the sun" but that is not as easy as it sounds.  Look up at the sun, where will it be in an Hour?  It doesn't have a trail or pointers!  But with stellarium, you can find where it will be in an hour  on your computer and then adjust your solar cooker stand to point exactly at that location.  This is far more efficient than guessing and generally guessing wrong.