Mine's 3 days(Friday to Sunday). Had some short naps though. We needed to fix a production issue which was not even caused by our team.:D We had to deploy a new version of our application(a replacement of the one which caused the issue) to resolve it. News reached us that we need to stay reached us on Friday late afternoon, around 5pm and we were able to go back home on Sunday afternoon. I was 15 younger then so I was able to cope. I even went to work the following Monday.
How about you, what's your longest stretch?
I used to work several back to back 300+h/mo months on a regular basis every time there was another "crisis" in a project because some idiot manager promised more than they should've, typically about 12-14h/day for 6-7 days a week.
It was stupid, the results were awful, and the pay wasn't good enough anyway. People need to not be proud of such things and find a better job when their managers treat them like that.
Nowadays I put a lot of effort into trying to not overwork myself so every hour I do work, I am at peak performance. I deliver much better value for the time and money spent, and when there's a crisis I can stretch a bit.