Abstract: A box has an external plug insertable in a video output receptacle of a computer with internal screws from the box to side screw holes. Locking the box cover prevents access to the screws. An external video plug receptacle receives the plug from the display screen. An internal circuit between the external plug and receptacle has a programmable microcontroller, a real time clock, and internal battery to control the amount of time and time of day video signals are sent from the computer to the display screen.

Abstract: A timed programmable control alters signals between an electronic device and a viewing screen to lower or eliminate a signal for a specific color on the screen at specific times. Eliminating or lowering blue color on the screen allows normal production of melatonin prior to normal sleep times to permit normal sleep cycles. The control may be a microcontroller or simple switch inside a locked box, a video card, or software to control light pixel values in memory, VGA signals, and digital to analog conversions.