You and I are in similar situations. 40 hours is a 3 day thing for me, as well... crunch time and it takes only 2 days to do 40 hours.
It’s funny in a sad way, isn’t it?
I have been working at this level since moving from my cushy engineering job in 1983 to software development/system admin. Most years the company scheduled a big software upgrade...on my birthday, Thanksgiving and Christmas. It's unfortunately the "norm" in the software business. I had one week when I racked up 80 hours by 7 PM Friday. Since I was only being paid for 80 hours, I headed home to Idaho for a week. Much of the project was working 230 to 240 hours per month for 160 hours pay. Better than being unemployed, but crushing to the max on health. I was doing the work of 4 Java programmers, 2 C++ programmers, 2 EE's and supervising my development lab.
My project controller just sent me a note for last week. The hours worked over 40 will be compensated at straight time instead of simply being uncompensated OT. My wife will be happy with that.