When Rotondo last updated Left4Block, he added some bits of code that find out if it's 9-19-09, and if it is, changes the zombies to pirates.
if(getword(getdatetime(),0) $= "09/19/09")//arrrgg
{
%client.hat = 5;
%arghh = getrandom(0,2);
switch(%arghh)
{
case 0:
%client.faceName = "smileypirate1";
case 1:
%client.faceName = "smileypirate2";
case 2:
%client.faceName = "smileypirate3";
}
return;
}