"What is Jace's birthday?"

I don't know. I don't really know the birthdays of any of the characters, unless it's germane to the plot (like Clary turns sixteen in COB, so I know her birthday's in August.) I was starting to think I was some sort of mutant so I wrote to several writer friends today and none of them know their characters' birthdays either, which made me feel slightly better.

I know this is the sort of thing readers like to know because it makes the character seem more rounded. It just isn't the sort of thing that actually helps the process of building a character (unless you are into astrology, which I am not, no disrespect, just don't know much about it.) You can sort of back-engineer Jace's birthday — Jace was "born" the day his mother died, which was before the Uprising, at which Jocelyn was probably about two months pregnant, so if Clary's birthday's in August, the Uprising was probably the previous December, which likely makes Jace a November baby (and about ten months older than Clary). So we might see his birthday in an upcoming TMI book after all.