Depends what it is, if it aint something too big then I'm fairly ok, but I will leave everything till the last minute, having a shower, getting dressed etc, that takes my mind off it for a bit.
But if I have to go do something like see all the family then I will sit and watch the clock for days until the time comes, I don't drink before I go out, but almost always do once I'm there.
This weekend I'm going away to my grandads army reunion with him and my dad, when he asked me to go last year I said yeah because it was so far away, but now its tomorrow, I'm really shitting myself, been waiting for it about a month now. The only good thing is that in just a few days time it will all be in the past.