5 - 7 - 9
Consecutive ODD Numbers.
Which happens only six times per one hundred years.
This is the third odd day of the 21st century, one in six. The reason it's called an Odd Day is because it features three consecutive odd numbers: 05/07/09.
See http://www.oddday.net /
The next ODD Days:
7 - 9 - 11
9 - 11 - 13
11 - 13 -15
Then oops, we run out of months



I saw that on Twitter! How odd....
Today is not the first odd day of the 21st century. The first odd day by your definition was 1/3/5, January 3, 2005. The second one was 3/5/7, March 5, 2007. So today is the third one of the century.
Julayne,
You are right. I just corrected my text. I think they call that a "brain fart". :-)