call it a day

present singular third person calls it a day · participle present calling it a day · participle past called it a day · past called it a day

1. idiomaticTo cease an activity.First known use 1919

   We have been at this for hours; let’s call it a day and come back tomorrow when we are fresh.

   1 more example

   “Do you often go looking for mice in other people’s rooms?” “I wouldn’t say often. Just when the spirit moves me, don’t you know?” “I see. Well…” When people say “Well” to you like that, it usually means that they think you are outstaying your welcome and that the time has come to call it a day. She felt, I could see, that Woosters were not required in her son’s sleeping apartment […]

   1960, P. G. Wodehouse, chapter 8, in Jeeves in the Offing

2. idiomaticTo retire.

   After suffering massive losses for three years in a row, the boss decided to call it a day, and sold his company.

   Synonyms: call it, call it quits, call it stumps

3. idiomaticTo end a period of activity, either because it is unsuccessful or because enough has been done.

   After he was reprimanded for slacking on the job, they decided to call it a day and fire Allen.