It was quite weird actually - we started at 3pm on Saturday and were expecting to work until about 2am (the joys of a global system - it's all about minimising the downtime for the "important" countries). Unfortunately, things didn't go quite according to plan so we didn't really finish until 5/6ish. I was supposed to be back in on Sunday at 8 for the start of testing, so I figured, I'll just work straight through.
At first, I was pretty knackered, but by the late morning I was surprisingly awake. The afternoon I seemed to keep going without any ill effects, but by 5 I was flagging. I thought about trying to see it through to the last checkpoint call (7:45), but decided home was the right decision!
I started a film at 8 to try and not destroy my body clock and wake up at 4am, but I fell asleep anyway, woke at 11pm, back to sleep, then up at 8am to spend another 8hrs online. Fun eh?
Got some great comments though, so I'm hoping that it won't have done the old career prospects any harm! I'll try and post some thoughts on the go-live in general later this week.