Maybe we should all adopt Chinese weekday names: Sunday (星期日) remains same, Firstday (星期一) for Monday, Seconday (星期二) for Tuesday, Thirday (星期三) for Wednesday, Fourthday (星期四) for Thursday, Fifthday (星期五) for Friday and Sixthday (星期六) for Saturday. One-letter abbreviations would be simply S, 1 through 6.

I believe that's how Russian names the days as well. In Hebrew and Arabic we do the same, but Sunday is First Day, Monday is Second Day, etc.

Why downvoted? This is correct.