I voted November, because I only know Kito's birthday. We got Abbey November 10 of last year, and they said she was about a year, so we celebrate them together
As for Riley, when I got him, I took him to the vet's and she said he looked to be around 12 weeks--it was the end of March, so I made up his birthday to be January 1!!!
As for "got you" days, Kito--August 2, Abbey--November 10, and Riley--March 28.