If I have an extra-productive day, where I accomplish more in 8 hours than I normally do, I don't expect to get paid more. I'm paid a salary, not per line of code.

The Thread Parent has cut down the hours that they are working, and cut their pay accordingly. But they also happen to be consistently more productive in those hours than they used to be. It wasn't a condition of their cut hours that they are required to work more productively, they just happen to be.

(Yes, ideally a good organization would reward this with a higher monthly pay. But that's a separate issue. I get paid the same as another developer in my position, even if one of us tends to be slightly more productive.)

If your goal to provide as little value to your employer as possible without getting fired?

If you're getting paid the same hourly rate it's still a win to work less.

I agree with you that getting paid the same hourly rate, working less and still maintaining job stability is a win.

It just didn't initially sit right with me when I heard Look at me I'm winning! I used to do five days of work and get paid for five, now I do five days of work and get paid for four.

They were doing four days of work and getting paid for five, now they do four and get paid to do four :)

I also went from 8 hour day to 6 hour day with a cut in pay and no loss in productivity and I feel it was a win. I've enough money either way and a lot more time.

Well, it's obviously a baked in assumption that the employer wants to provide as little remuneration for value as possible without alienating the employee. In theory our compensation is based on some combination of the value we deliver and our negotiating strength. If we deliver the same value in 80% time and take home 80% of the compensation, we've fully left negotiating strength on the table.

Your assumption is that they were doing 5 days worth of work in 5 days, and now they're doing 5 days worth of work in 4. But they're just more productive, they're not busier. So it sounds like before they were doing 4 days worth of work in 5.

I think it really depends on what the work entails. When I’ve worked on some particularly complex problems it’s often the case that I get “zero” days’ work done for four days, then “dozens” of days’ work done in one. My assumption is that a person has a fairly fixed productivity capacity over a given stretch of time, that we as a society tend to organize that as a week of seven days, and that it’s highly likely most people (again depending on the work and the person) reach that capacity in less than five days.

It depends on how much your time is worth to you. If you’ve got nothing better to do than hang out at the office and take it easy on casual Fridays, then you might as well get paid for it.

If, on the other hand, you’d rather go home and put your 3 day weekends to better use taking care of your household, spending time with family, engaging in a hobby, travelling, or relaxing at the cottage (if you don’t own one, you might try renting one), then your Friday is more valuable to you than the money you lose from taking the day off.

Do you really think you're working all day every day?