ComputerCraft: 'lamp' turns on lights at night.

--v1.0 by GraySloth 2013-Feb-15
--variables
local sSide = ("top")
--functions
function clear()
   term.clear()
   term.setCursorPos(1,1)
end

function on()
   redstone.setOutput(sSide, true)
end

function off()
   redstone.setOutput(sSide, false)
end

function pulse()
   on()
   os.sleep(1)
   off()
end
--Main
while true do
   if (os.time() < 6) or (os.time() > 19) then
      on()
      os.sleep(1)
      print("Night")
   else
      off()
      os.sleep(1)
      print("Day")
   end
   os.sleep(1)
   clear()
end