In the show they have Game 5 beginning on October 28, 2008. The game actually started October 27th and wasn't completed until the 29th because of the rain delay.
Dee says that Chase Utley is "like five years younger" than Mac. Utley was born in 1978, and all indications are that Mac is the same age as Rob McElhenney (the actor portraying him), meaning he was born in 1977 and is therefore only one year older than Utley.