> That said, this sort of arrangement seems to be extremely rare in the US

No, this is pretty common in government and government contracting. It's called an RDO: "regular day off"... more commonly known outside the US as a "rostered day off".

When I was a contractor we had even more flexible arrangements: we could work whatever hours we wanted, as long as they added up to 80 every two weeks. Eventually this got abused enough it was cut down so you could shift at most 10 hours between week 1 and week 2, but you could still, say, work just four 10-hour days every week.

This is also called 9/80 in defense jobs.

Or "CWS Day" - Compressed Work Schedule. Four 9-hour days and one 8-hour day one week and four 9-hour days the second week for a total of 80-hours for a two week pay period.

We used to have offices in New Jersey, just outside New York City, and they had four 10-hour days each week. (Supposedly a state law?)

I do four tens and a little known feature is by missing rush hours I still spend 40 hrs in the office but I spend MUCH less time away from home, I spend much less time in my car. five eights is an hour each way in the car ten times a week thats 50 hours away from home. for tens is 20 minutes each way eight times a week thats about 43 hours a week away from home. Its like getting a free day off every week! Also I burn much less than 4/5 the gas because no stop and go!

4x10 is what I pulled at Microsoft; actually 9, 10, 10, 11 hr shifts. It worked out really well but did occasionally cause headaches with scheduling.

This sounds like such a good idea. One of the main problems I have working 9-5 is scheduling things like doctor and dentist appointments, bank visits, government paperwork, etc. I have to take a vacation or sick day just to get normal things done.

I interviewed at a Raytheon office in Rhode Island as a college grad in 1999 and they did this too then. Not sure if it's still in place or if it's a companywide thing.