One of the most used phrases used in business is "at the end of the day"; which is usually invoked when referring to something that has results in some significant consequence or meaning.
So I am sitting at my kitchen table at the end of today pondering what the end of the day entails for me. Is it really the culmination of a day?
In my experience, the end of the day usually means a break from work. Rather than being the end of my work, the end of the day is a chance to regroup and prepare for the next day.
Even when it comes to major decisions, one normally "sleeps on" a decision, making the choice by the next morning.
So while the end of the day is the finalization of a calendar day, it is mentally the start of the next, a chance to pull back and see the big picture.