Death by working late

And by late I mean 9am to midnight. So... Late. Or maybe early? We're working on a system upgrade that we -have- to do, or else we literally will not be able to send any marketing. So yes, have to do it, to the point that we stayed at work till 11:30 then went home to continue working there. AND, it failed :( so now we're going to do this all again on a weekend.