What is the origin of the idiom "at the end of the day" and when to use it?

The idiom "at the end of the day" is thought to have originated in the 17th century as a way to refer to the end of a workman's day. It was later adopted into figurative use to emphasize what is ultimately important or what matters most. It is often used to contrast the immediate or short-term with the long-term or ultimate consequences of something.