Depending on how you calculate it, the Leap Year cocktail either turned 86 this year — or is just embarking on its 20s. We know this because the exact date this drink was invented is documented in the Savoy Cocktail Book, bartender Harry Craddock’s popular mixing manual, first published in 1930. This blend of gin, orange liqueur, lemon, and sweet vermouth was born on Leap Day, 1928.