The party will commence on Friday, February 12th, at 1 PM PT (4 PM ET) on SOE's Ustream channel. The community team will be gathered to make paper hearts and answer your questions live in the Ustream chat room while they deliver player submitted Valentine's Day greetings and announcements. SOE developers will also be dropping by the party to talk with players, so you never know what will happen!
Today, however, is the last day to submit your own personal greetings to the party! The full instructions are available at the official announcement on any of the SOE sites, but you can be lazy and click this link to go straight to them on the EverQuest II site.