Board Thread:General Discussion/@comment-7526254-20150520160921/@comment-25926288-20171221172756

An interesting aside, an addition to this discussion in part, Henry's timeline with respect to the canon companion novel excerpt, Henry and Voilet.

Henry was born August 15, 2001.

Henry, age 10, was in 4th Grade in the 2011-2012 school year. (Mary Margaret says that she teaches fourth grade in season 1)

Violet and her father move into Storybrooke in 2014(?). (Chambliss' timeline had the events post Camelot Quest to be roughly two years after the Curse broke (or when Emma came to Storybrooke?)).

Violet recounts her first Christmas Eve in Storybrooke and how it has been about 3 years.

Henry, age 17, attends a trip to NYC during 11th Grade at the end of the 2018-2019 school year.

So, going by Adam's "secret, secret" tweet, Henry does graduate highschool, which lands him in the year 2020 (unless cursed memories bumped him up a grade).