The Watchtower (WT) says this about Valentine's Day.
' “Saint Valentine’s Day.” There are various theories regarding the origin of this “Christianized” name. According to one story, the third-century Roman emperor Claudius II forbade young men to marry. Valentine, a priest, married young couples secretly. Some say that he was executed on February 14, about 269 C.E. In any case, a “saintly” title cannot conceal the unsavory origin of this celebration. Valentine Day is rooted in pagan rituals and is therefore not celebrated by true Christians.' Watchtower Feb 8, 1995, Article: 'A New Name for an Old Orgy', par 7