call it a day

Verb

call it a day (third-person singular simple present calls it a day, present participle calling it a day, simple past and past participle called it a day)

1. (idiomatic) To cease an activity.
   • We have been at this for hours; let’s call it a day and come back tomorrow when we are fresh.
   • “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....1960, P. G. Wodehouse, chapter 8, in Jeeves in the Offing
2. (idiomatic) To 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. (idiomatic) To 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.