Well, my birthday is in August so I have no business judging you on this
Couple of qualifying questions:
1) By birthday ride, do you mean riding your age in miles?
2) If yes to
#1 , then it kind of depends on how old you are. Well, that wasn't a question but didn't seem right to ask
Personally, I'm not too OCD about riding my age (or more) on my actual birthday as long as I do it some time on or after that day during the season.