In writing classes, adding all of that unnecessary dialog is considered insulting to the audience. If you are trying to write a joke for the lowest denominator audience member, then you will alienate a larger portion of the audience. If every single joke needed that much additional context, it's not a funny joke. If you're going to require the writers to add that much dialog, you might as well ask them to add a laugh track

I'm not adding context to the joke, I'm pointing out that people are misinterpreting the dialog as it was written. by saying "I don't know what the additional context is", I was saying "perhaps she had just said TGIF!" and that would explain why he said "it's Wednesday"

"What a week, thank god it's over!"

"it's wednesday"

would work for your lowest common denominator.

Truth be told, that's all the one of the differences between American and British comedy.

Slapstick is cool, but irony needs to be understood.