Q. What is the speed of light in miles/hour?
Q. The Sun is 93,000,000 miles away. How long does it take for the light that leaves the Sun to reach the Earth?
Q. What is a Light Year?
First, this is a unit of DISTANCE (not time). It is the distance light travels (in a vacuum) in 1 year.
The most distance objects we have observed in astronomy have ``look-back'' times of > 8 billion years. The finite speed of light is very handy in that it allows us to look back in time...