Let your significant other pick the date, and then take the day off from work by calling in sick, catching hell from the boss, whatever you need to do. Then, sleep in, go to a museum or the movies (matinees are cheaper), take a serendipitous walk, venture off into the woods on snowshoes — do something you don't normally do on a weekend or holiday. There's an extra secretive, conspiratorial thrill to goofing off on a day when most people are at work.