Birthday Season is an annual tradition celebrated by the Club to commemorate the strange phenomenon of their birthdays falling within one month.
Following his death in 1696, Black John resurrected himself and returned to Crowhaven Road on the fall on 1974. He went under the alias of John Blake and charmed both the elderly and young generation living there. Soon, Black John paired off the young witches together, and got them to start up a Circle to practice the old ways of witchcraft.
Soon after the handfasting weddings in March, the females of the Circle were heavily pregnant and by October, it began taking a lot out of the women. From November up until early December, eleven babies were born and each of them already showed an affinity to magic. Only then did Adrian Conant realize the truth behind the childrens' birth: Black John planned to use them to form the strongest Circle ever seen in the country.
With that knowledge, most of the parents set off on Imbolc night (February 1, 1976) to confront Black John. They managed to burn him alive, but a hurricane Black John summoned killed all the parents. The survivors were the ones who were too ignorant and refused to fight Black John.
- November 3: Nick Armstrong
- November 5: Adam Conant
- November 7: Melanie Glaser
- November 10: Diana Meade and Faye Chamberlain
- November 17: Chris and Doug Henderson
- November 24: Suzan Whittier
- November 28: Deborah Armstrong
- December 1: Laurel Quincey
- December 3: Sean Dulany
- Both Cassie Blake and Kori Henderson's birthdays fall outside of Birthday Season. Kori was murdered by Black John because her birth wasn't planned, as well as to ensure Cassie would become part of the Circle.
- Laurel and Sean are the only members to be born in December, while the rest were born in November.
- When Cassie first became aware of Birthday Season, Suzan jokes that it was a "very wet April" that year. This would mean that the Circle was born approximately two months before their due dates.
- Diana and Faye's birth was the most strangest, according to Maeve Howard. Their mothers were sisters and they were born at the same moment in different houses. Ironically, Diana and Faye are polar opposites to each other as seen in their appearances and personalities.
- In the TV series, the Circle (with the exception of Nick and Jake Armstrong) were born one month apart in the same year.