at the end of the day

The first time I was conscientiously aware of the cliche "at the end of the day" was in August 1999, while talking to a friend in Germany. The reason I remember this useless bit of detail is because I've always known the phrase to be "by the end of the day," which takes on a somewhat different meaning. From that point on, I can't recall one instance where someone said "by the end of the day." It's as if "by" was instantly and forever replaced by "at."

It seems to me "by" represents a literal time in a 24-hour day, and "at" is something that you say before you say what you believe to be the most important fact of a situation.

How do I feel by the end of the day, Are you sad because you're on your own?--- Ringo Starr

I hear what you're saying, but, with all due respect, it's not exactly rocket science. Basically, at the end of the day, the fact of the matter is you have got to be able to tick all the boxes. It's not the end of the world, but, to be perfectly honest with you, when push comes to shove, you don't want to be literally stuck between a rock and a hard place. Going forward we need to be singing from the same songsheet but you can't see the wood from the trees. Naturally hindsight is 20/20 vision and you have to take the rough with the smooth before proceeding onwards and upwards. The bottom line is you wear your heart on your sleeve and, when all is said and done, this is all part and parcel of the ongoing bigger picture. C'est la vie (if you know what I mean).---Nick Godfrey

I shudder to think I had this phrase wrong my whole life. But maybe "at the end of the day" overtook "by the end of the day" as the phrase du jour as a symptom of the new world-wide corporate environment we all seem to be shackled with.

By the end of the day, December 21, 2012, we'll all be at the end of the day.--- Lofas F. Pigman
(I think I just found the exception to this rule)