clock watcher
noun
an employee who demonstrates lack of interest in a job by watching the time closely to be sure to stop work as soon as the workday or shift is over.
any person who watches the time closely, as in expectation of some news or event.
Origin of clock watcher
First recorded in 1885–90
Dictionary.com Unabridged
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019