Longest stretch of work for me was 63 hours. I spent a summer writing an enormous batch file to handle a Netware 3 to Netware 4 conversion. I got the job for being the intern that no one quite knew what to do with, but I could program, so someone had the bright idea to give me this job. So I spent several weeks manually upgrading Netware servers and figuring out how to script what I could.
Anyway, the idea was that the script would get run on Friday night and we'd have all weekend to iron out whatever problems resulted from it. Me and four of the most senior Novell people manned a call center and all the rest of the IT staff + contractors were sent out to actually run the installs on all these servers.
All in all I think it did work really well. There were 385 servers and I think my script worked right on 340 of them. The ones where it didn't, though, we spent all weekend and in to Monday morning trying to fix. Two of the "senior" people I was working with had never done an upgrade to Novell 4 and turned out to be mostly worthless, and some of the people in the field were Unix people with no experience dealing with PCs, let alone Netware, so those of us who were supporting the installers didn't get much of a chance to take a break.
It pretty much sucked.