I had a work schedule that was exactly the double of that:
Sunday and Monday off…
Then work ten days (Tuesday through Thursday of the following week)…
Then Friday and Saturday off.
So, four days in a row off, then ten days on.
It had to be exactly those days in order to have 4 days in a row off, because legally we still had to work just 40 hours in each Sunday-Saturday week, if we did more they’d have to pay overtime. So by giving Fri-Sat off one week and Sun-Mon off the next week, they avoided that.
(And on top of that, I got paid 15% extra for being on the midnight to eight shift.)
Oh, and we worked straight 8 hours with no breaks, not 9 or 10 with breaks. But of course we took breaks, covering one another’s stations for each other. All the shifts did this, but it was easiest on the night shift because things were generally quiet and slow most of the time (compared to the madhouse that was the day shift). And for this we got paid 15% extra!
Oh, and we did nuclear weapons research, so we didn’t like to call it the “graveyard” shift. We always called it the “Owl” shift.