GOGOGOGOGO!! Fingers on those print-screen buttons, folks, and get ready with the champagne/tissues, 'cos this is the last repeating date you're ever gonna see in your life. Ever.
Whilst it's not quite got the elegant minimalism of 11/11/11, this is still a Big Deal. Never again will you have the pleasure of glancing down at the bottom right of your screen (or top right, for you closet Mac fans out there), and see a beautiful row of identical digits. (Unless you go and manually reset the clock, of course.)
Mashable's got a list of all the fun things you can do to celebrate this momentus day. Me? I'll be running round the internet, screen-capping things like mad. Then hiding in my nuclear fallout shelter waiting for the apocalypse. How 'bout you good folk?