What you’re asking is not written explicitly in canon, iirc, but fandom has generally accepted the following info, maybe bc AR told us over the years? I don’t remember when we were told…

• Lestat’s birthday is November 7, the birthday of Anne Rice’s late husband Stan (whom she partially modeled Lestat after).
• Louis’ birthday is October 4, which is Anne’s birthday.
• Claudia mentions her birthday in her diary (in QOTD) as being September 21, but she’s not sure if that’s really her birthday and her dads won’t explain it further

  (it’s probably the day she was turned, given the context of the diary entry). That’s Michele Rice’s birthday, Anne’s late daughter.

So Lestat is a Scorpio and Louis is a Libra. I don’t know much about astrology, you’ll have to take it from there, anon!