This coming Saturday is a special day. In fact, it's a once in a lifetime---89 years to be exact---type of day. News agencies started writing about it last year, Las Vegas is offering special wedding packages for that day, and even Walmart is joining in on the celebration.
The next sequential calendar date is January 2, 2103 (01/02/03)---about 89 years from now. If that's not enough motivation to do something special on Saturday, here are some more (mathematical) reasons.