User blog comment:Dtuck010/Nightwing's Birthday/@comment-5145408-20120613223405

whether it is or isn't his birthday in this universe continuity we won't really know unless they decide to mention it.

but i don't think dick would draw attention to himself by a birthday celebration (besides, his ID is secret, so why would he get in to that sort of personal info... unlike wally where everyone knows who is his behind the mask and his personality is one where he'd be all in to a birthday party for himself).

given that this season is shorter they have more overall plot to cram in that the side stories (which couldinvolve a character development moment like a birthday) would get cut for time.

Given that season 1 was july - december, and season 2 is jan - june, we're covering all the months so eveyrone would have had a birthday in one of the two seasons even if not openly mentioned/celebrated on screen