There's no date to set! Although there will certainly be time specific promotions and events, the convention itself is just a fun metaphor for the community group. It's 24 hours a day, 7 days a week, 365 days a year just like the Steem blockchain!
Keep contributing with great content and discussion in the comics and related tags, and just be on the lookout for any future community projects you may want to participate in! Likewise, if you have a fun idea in mind please suggest it!