A hybrid of yesterday and tomorrow. The two cancel each other out, so in the end you just have an unnecessarily elongated form of today.
Employee: "How are you tomterday?"
Customer: "I was doing just great until you fucked everything up by using tomterday. By the way I need a pack of condoms."
(n.) A saturday on which one ruins, distresses, or even destroys articles of clothing and makes them look even more fly and fashionable than they already are. Ex: t-shirts, jeans, etc.
Person 1: "You do anything fun this weekend?"
Person 2: "Yea, my Tatterday was actually quite productive. I made a few new tees, they're so sick."