http://www.pcgamer.com/bungie-community-manager-confirms-destinys-crimson-days-event-is-coming/

With the Destiny 2 holiday event The Dawning now wrapped up, it's time to look ahead to what's coming next. According to this Reddit thread, which now comes with an all-but-official confirmation from a Bungie community manager, players still soldiering on through the waist-high salt drifts can expect the return of Crimson Days. 

This event first appeared during Destiny 1's lifespan, and is a Valentine's-like celebration of lovers and killers. Assuming it follows roughly the same structure, it will bring a new PvP mode and new ghosts, sparrows, and weapon ornaments to collect by either grinding the game or shelling out for time-limited special engrams. Of course there's a good chance the Destiny 2 iteration of Crimson Days may work differently, but assuming it doesn't here's what the Destiny 1 Crimson Days page says: