Board Thread:Character Discussion/@comment-3966122-20140915204847/@comment-15736398-20141019173459

Henry was 10 in the Pilot (which begins on October 23rd, 2011), 11 in "Manhattan" (which takes place at some point after the events of "Skin Deep", which took place on February 14th, 2012), and 12 in "The Jolly Roger" (which took place after the 1-year time jump). Given that the show has only reached early 2013 internally (even with the 1-year time jump), his birthday is most likely in the late Winter/early Spring (otherwise, things don't line up).