When I worked a 9 to 5 job, my boss would say he wanted it Monday. To me that meant COB (Close of Business) Monday, which meant when I left to go home - even if it was 10 pm.
In fact, if I slipped it under my boss’ door on Tuesday morning, before he got in, I still counted it as Monday. After all, I could claim it was Monday evening. All he could do was smirk. He could never yell at me, because he had it in his hand.