In the nick of time means at the very last possible moment. Arrive in the nick of time, caught in the nick of time, just in the nick of time.
The relief is built into it, so the phrase only describes things that turned out well. The nick was once a notch cut to mark a score, which is where the sense of an exact point comes from.
1phrasein the nick of timeAt the very last possible moment.
“The ambulance arrived in the nick of time.”
in the nick of time is a phrase.
Also accepted in games: just in time, at the eleventh hour
Practised in Idioms