There are exceptions. For example my current employer, a decent-size public company, allows employees to purchase up to one week of extra vacation time each yea

There are exceptions. For example my current employer, a decent-size public company, allows employees to purchase up to one week of extra vacation time each year. (Straight time—equivalent to unpaid time off, but with the cost spread out over the year in the form of reduced pre-tax salary and no change in other benefits.) I've known several coworkers who did the 4-day-week thing for months at a time rather than taking long vacations. They are also open to negotiating shorter hours or alternative schedules.