the.com/nick of time

means At the very last possible moment, just before it would have been too late.

from 'Nick' once meant a precise notch or small cut — the kind used to mark exact measurements or tallies on a stick. A 'nick of time' was originally the exact, critical instant, as precisely marked as a notch cut into wood. The phrase survives from 16th-century English long after anyone carries a tally stick, but the idea of time sliced to its thinnest possible sliver remains exactly intact.