watch the clock
From Longman Dictionary of Contemporary Englishwatch the clockwatch the clockinformalNOT DO something to keep looking at the time because you are worried or bored anxious mums watching the clock → watchExamples from the Corpuswatch the clock• I am watching the clock, counting the minutes till the last period of the morning is over.• She watched the clock hands go round.• And watched the clock so he could call a halt to it as soon as possible.• Only then did she let herself watch the clock to the strains of Beethoven's Apassionata.