Okay, so in the episode where Antonio's date-packed weekend encourages the other four younger characters to join the video dating service, they're asked "What's your sign?" in the interview.

They all give an answer (well, except Lowell who pauses and looks around him, then asks, "What sign?" ha), and whilst watching I wondered if they let the cast members answer based on their real birthdays, just to keep the lines easy.

Oddly enough they did, except for Tim Daly, who I guess had to change his to Capricorn because Steven Weber was also a Pisces.

Helen said Libra (Crystal = Sep 30)
Joe said Capricorn (Tim = Mar 1, Pisces)
Brian said Pisces (Steven Mar 4)

(I realize I may be the only person who finds that interesting.)