clockwatcher
nounUK /ˈklɒkˌwɒtʃə/
US /ˈklɑːkˌwɑːtʃər/
A clockwatcher is someone who keeps looking at the clock because they want to go home.
The teacher said the clockwatcher kept staring at the wall clock during the last lesson.
OTHER MEANINGS
2. An employee who does only the minimum work and waits eagerly for the end of the day.
The manager complained that the new hire was a clockwatcher who never stayed a minute late.
3. A person who is overly focused on measuring time precisely.
As a clockwatcher, she timed every task down to the second.
4. Someone who is impatient for an event to begin or end.
The children were clockwatchers on the last day of school before the holidays.