Time indeed slows down around a black hole according to Stephen Hawking. Now this phenomenon happens because of the super gravitational force of the black hole. By virtue of this enormous force the black hole warps the space-time present all around it to such an extent that time around it slows down considerably.

Can black holes slow down time?

As you get closer to a black hole, the flow of time slows down, compared to flow of time far from the hole. (According to Einstein's theory, any massive body, including the Earth, produces this effect. ... Near a black hole, the slowing of time is extreme.

What is 1 hour in a black hole?

When considering general relativity and special relativity, the time for an observer dilates when falling into a black hole. The closer the observer reaches the event horizon, the times dilates more. This means that 1 hour for the observer will be 100000000 years for a person on earth.