Saturday will be the last time this century that the date will consist of consecutive odd numbers.
The date will read 9/11/13 and the unusual sequence of numbers will not be repeated until March 1, 2105 (1/3/5).
Ron Gordon, a retired teacher from Redwood City, California, has urged people to celebrate the day.
He has set up a competition with a prize fund of the date in US dollars ( 911.13) to be shared by the 33 people (9+11+13) who make the best effort to mark the day.
Writing on his website OddDay.net, he stated: " Prizes will be distributed to those who involve the most people in the oddest parade of odd characters, write the best odd ode, or create the best odd celebrations."
Mr Gordon, who noted that some countries including the US will have their final Odd Day on 11/13/15 , called on people to greet their friends with "the news of the day".
He wrote: " 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!"
His suggested activities include doing your odds and ends around the house, rooting for the odds-on favourite and finding a missing odd sock.
Mr Gordon, who also celebrates Square Root Day, added: "A s odd as it is, the 9th of November b rings a glorious day we will always remember. This won't happen again for 92 years."