Oh, how embarrassing. When George is talking to Susan's grave, he says, "And then after the All-Star break, we swept the Orioles--four straight. In Baltimore!" (quote not necessarily exact.)
For those who aren't baseball fans, that is a true statement. The Yankees led our Orioles by six games when they came into Baltimore for a very big four game series. If the O's swept the Yankees, the Yankees' lead would be only two games and the pennant chase would be on. As it turned out, the Yanks swept the O's, extending their lead to 10 games and pretty much knocking the O's out of the running. (As it turned out, the O's scratched their way back into the pennant race, but coincidently during the airing of Thursday night's episode, the Yankees were once again were knocking the O's out of contention.)
(I liked it better when Elaine was wearing her Orioles hat at Yankee Stadium - years ago.)
I thought it was interesting how "Seinfeld" (the show) has come to using a real life calendar. The wedding was going to be on the first day of Spring, then it got pushed back to June, then Susan died, and most interestingly, during the summer, it was like their lives still went on, but we just weren't watching. There was reference to the three months of mourning, That Unfortunate Yankee Series, the Fourth of July, and Elaine being gone for six weeks to kind of remind us that, yeah, we've been gone for a while, too. Most shows, I submit, aren't like that. You come back in the fall and it's five minutes after the previous season's finale ended. (Case in point - "Mad About You".)