You have to enroll the month before your birthday. Sammi runs the birdthday club, I believe. If you're enrolled in time then for your birthday you get a $25 gift card. I believe they give them all out at the start of the month.

Actually, it's Darling Jen that runs the birthday club
The September birthday club is here, and it has the information for how to submit your birthday.

Thanks! Two months to my birthday so plenty of time to apply!