call it a night
to end doing what you are doing in the evening and go home or to bed
„At midnight I called it a night and went straight to bed.“
„The band played a few more songs and then called it a night and left the stage.“
„We’ve done enough today. Let’s call it a night and get some rest.“
Let’s call it a night. = Pro dnešek stačilo. Pro dnešek to zabalme.
go by the book/do sth by the book