Least productive

What day of the week do you find you are the least productive at work?
I am finding that my least productive day is not one that I would expect. After a crazy busy week (most weeks) and I finally get a day to be productive that happens to fall on a Friday…yeah, that’s my least productive day.
Not because I am thinking of the weekend plans or trying to give myself that stupid buzz-word, “self-care.” I am just out of motivation.
By the end of the week, I could care less if I get anything done.
I am sure my employer would hate to hear that. I actually don’t like to hear it because I really have a ton to do (catch up on email, start projects, complete unfinished projects, etc). But, I just can’t get myself to do any of it. I look at what I have to do, my list of things to do, and all the other stuff sitting on my desk and I just can’t.
Is this normal? To just run out of productive steam at the end of the week?