Depending upon mass, time can go faster or slower. The Atomic time at Greenwich is only right for that latitude and altitude.

If we didn't correct for this relativity, GPS would go wrong in moments.

If you race away from the face of a clock AT THE SPEED OF LIGHT (impossible) the time on the clock would not change from your point of view even if you could see it a parsec away. Has time stopped?
No, it just looks that way to you. Your own watch will give you a more accurate indication of time lapsed.