Well, it should't be a day off, you should do something that has to do in general with what you do at work if possible.
I haven't though about it that much, it was just an idea. If you get the day off, most people would probably just do what they want and "waste" the day (which means not being productive).
This whole idea of being productive every single day is why burnout happens. Using that extra day to not be productive (say, get the shopping done while the shops are quite and everything is open) means you can spend the weekend relaxing, so you're way more productive come Monday.
Been there. Most people are not motivated enough to do something like that, and it ends up feeling like a chore. In that case it's more productive to not be at the office.
It makes some kind of sense: boxing the time for creativity ends up killing it.
From the rest of your comment, it seems to me that the feeling that it's a chore might be more the reason it kills creativity - not the setting aside time in and of itself. If you don't look forward to that time (not saying that's a bad thing, one way or the other), you probably won't get much out of it.
What I meant is that it can feel like a chore because it's something 'imposed' by the company. You have to do creative work on xxdays - doing it any other day is a waste, 'cause xxday is the alotted time - and it has to be related to your job, otherwise it's a waste too. It's not a very happy proposition, as good as the intention may be.
