From the Odd Day Website:
"Odd Day is Saturday, 7/9/11. Three consecutive odd numbers make up the date only six times in a century. After 7/9/11, only two days remain in this parade of Odd Days which began with 1/3/5. The previous stretch of dates like this started with 1/3/1905---13 months after the Wright Brothers' flight.
Things to do on Odd Day: It's a great day to do your odds 'n ends, give a friend a high-five, root for the odds-on-favorite, read the Wizard of Odds, watch the Odd Couple, say aaaahd in the doctor's office, look for sea odders, find that missing odd sock, and beat the odds.
Odd numbers are the unsung numerical peace-keepers---if it wasn't for odd numbers, all the even numbers would bump into each other!
These days are like calendar comets---you wait and wait and wait for them, then they brighten up your day---and poof---they're gone!
The simplest way to celebrate Odd Day?---just share it with friends. Greet them with the news of the day (they'll be awed)---and they, in turn, can tell another. It's kind of like a secret that you can't help sharing. A little math, a little smile, a little fun---that's Odd Day!
Odd Birthdays---if you didn't get one this year, odds are you'll get an Odd Birthday next year. (and you probably had one last year too!)
And why don't we celebrate even day? That's easy---it's one thing to encourage folks to do something odd for fun. But it's very different to urge them to get even with someone."