Valentine's Day is a Valentine's Day themed seasonal event that originally occurred in 2011 and then was discontinued due to quality concerns.
Valentine's Day resurfaced in the DCUO world in 2013 when a mission appeared in all player journals granting access to the styles and feats of the original event. In addition two special Valentine's Day related base items were dropping in The Vault.
This was continued for new player characters in 2014. Additionally two new style items and two new base items were introduced.