The Panagbenga is annually celebrated in Baguio City whereas the opening is always the 1st of February and closing is the 3rd of March, though normally it closes on the Sunday of the first week of March.
It will be all up to you if you'd like to stay that long, but I'd prefer seeing the main events since I can't really be out of office that long... gotta work you know
If you guys weren't there and you were busy... really busy during Valentines. LOL. I've got snaps for you of the recently concluded Hot Air Balloon Festival 2015.