Why do clocks run clockwise?
 
According to Henry Fried, one of the foremost Horologists in the United States, there is a simple explanation.  Before the advent of clocks we used sundials.  In the northern hemisphere the shadows rotated in the direction we now call "clockwise".  The clock hands were built to mimic the natural movements of the sun.  If clocks had first been invented in the southern hemisphere Fred speculates that "clockwise" would be the opposite direction.
 
from Why do Clocks Run Clockwise? And Other Imponderables