Happy Valentine’s Day! Want to show your sweetheart how smart you are about this tradition? Share these Valentine’s Day fun facts over a romantic candlelit dinner: King Henry VIII declared Valentine’s Day an official holiday in 1537. The oldest handwritten Valentine was made in the 1400s and is held in London’s British Museum. About three percent of pet owners buy Valentine’s gifts for their furry friends. About 110 million roses are sold for Valentine’s Day (during a three-day period) and about one billion Valentine’s Day cards are exchanged every year.