You have one; the first time you use it you accidentally cross paths with yourself, creating a paradox in which you and yourself are sucked through a tear in the fabric of reality and crushed into a singularity. The tear you made in the universe remains a source of strange events, so the military build a base over it, spawning an outbreak of area-51-esque conspiracy theories.
Also, I have no idea what MoR stands for; the Time Turner appears in the Prisoner of Azkaban.
I wish my office was always a comfortable temperature, instead of being too cold in winter and too hot in summer.