Hmm, if I'm parsing your sentence correctly, yes, I used to work 5 days a week, I requested it be changed to 4 (with a 20% reduction in pay), and they agreed. I can also go back to 5 days if I want, since they've indicated they would prefer that, but I strongly feel that a 5-day work week isn't a good fit for me right now.
I've been thinking about whether is reduction in the workweek is politically or culturally possible, even if it is economically motivated. I sort of came to the conclusion that people turning 5 days jobs into 4 would be necessary on the cultural front. Glad to hear of someone that actually did it!