negative 186,000 mi/sec.
Dark is the absence of light. Therefore it has no speed since it doesnt move. Will be there if there is no light. However, You can measure how fast the light goes away. The speed of light is 299,792,458 m / s.
It is faster than the speed of light cause it does not matter how fast light travels darkness is a head of it...lol
When the light fades, the dark will form at the same rate as the diminishing light
Speed of thought.
The capacity of lies.