I hope that it was clear that I was being somewhat tongue-in-cheek about the Monday thing.
Back to the original topic again! This is not a vocab coincidence, but a grammatical one:
I’m working today.
今日、働ています。
I’m at home on Friday.
金曜日に家にいます。
It doesn’t make sense to say “on today” or “今日に” in either language, nor would you leave out on/に in “on Friday”/“金曜日に”. It feels unusual when the preposition/particle usage for named times happens to line up between languages.
Whatever, I just love this coincidence.
Most of the Middle East now has Friday-Saturday weekends (like Qatar, which is where I am now). Wikipedia’s not aware of any countries that still do Thursday-Friday.
Fun fact: Brunei’s weekend is Friday and Sunday (and back to work on Saturday in between) which I think is the daftest thing.
Wikipedia says Iran’s workweek ends halfway through Thursday, I guess that’s sort of a compromise between Thursday-Friday and Friday-Saturday weekends?
Wow, Brunei sounds bonkers. For more fun, http://yourcalendricalfallacyis.com/ (and other such lists).
you only use に to point to Friday if the day is the target of something.
今日は働いてる。金曜日は休むので、家にいるけど、
土曜日までには論文を出さなきゃなので、その日も忙しくてごめん。飲み会を土曜日の夜にしてくれない？
let me add a beginner example, too.
月曜日、初仕事なんだ。金曜日までは忙しい。散歩を土曜日にしないか？