What does the cryptic crossword clue "Mark clock setting (4)" mean?

The definition part of the clue is "Mark / clock / setting". The answer is SPOT. Explanation: triple definition.

Mark clock setting (4)

Times Puzzle #28533 6 Across 2023-02-22

Definition

Mark / clock / setting

Explanation

triple definition.

Source: Times for the Times

Answer

SPOT