I've heard that if you leave one on for approximately 148.327 and 1/4 days . . . it might burn your screen (if said time span includes a Blue Moon). Which mens it's very unlikely in this day & age.

You could create a macro that looks something like this:

> DVD POWER ON
> DELAY 0.01  DELAY may need to be as high as 2 or 3 seconds.
> DVD STOP

Probably doesn't include Software to play VCDs.

Oh . . . please see Rule #33.