Following the podcast argument, I'd say you bring it up when you're ok to talk numbers. At that point, ideally you've already "made them want you" enough, that losing one day could look like a price worth paying. You should probably be honest though, and talk about it upfront as soon as compensation negotiation starts, accepting (or even suggesting) they could lower their salary range in exchange. Or simply negotiate on extra holidays, so you can use extra days to actually get a 4-day week once or twice a month.
If you're a super-hotshot ninjastar who wrote Rails and founded a Linux distribution that now runs the Japanese train system, then you could probably get both a spectacular salary and part-time hours, but realistically the two will not go together for most people. (Which, incidentally, is a typical problem for women with families and one of the reasons their salaries remain lower on average.)
If you're a super-hotshot ninjastar who wrote Rails and founded a Linux distribution that now runs the Japanese train system, then you could probably get both a spectacular salary and part-time hours, but realistically the two will not go together for most people. (Which, incidentally, is a typical problem for women with families and one of the reasons their salaries remain lower on average.)