Ya, I worked at a place with 12 hour shifts for well over a decade, often 6 days a week. It was from 7 am to 7 pm day shift, 7 pm to 7 am night shift, and would alternate every two weeks.
It was good money but I missed a lot of my two kids growing up. I wish I could say that at least it got me ahead financially, but my ex spent money like it was going out of style. I probably would have been better off flipping burgers and staying close to home.