@Maltimore Here it is (ignore the drop to 0 at the right, missing data). So ~200 fewer Japanese editors log in during the work-week than the weekends, around 9% (which is similar to the drop between Mon–Thurs and Friday for the English Wiki).

I'll be predicting daily editing activity, so I'm really interested in finding reliable trends to remove from the data before training prediction models, and the day--of-week is a great predictor. I'll post some other cycle analysis in a few hours.