LONDON (AFP) – Notice anything exceptional about today's date? It's July 5, 2009 (05/07/09) -- and three consecutive odd numbers make up the date only five times in a century.

This nugget is pointed out by Californian high school maths teacher Ron Gordon, a self-confessed "mathemagician".

"This really is a day to celebrate. OK, it's true there will be another one in two years' time on September 7, 2011 (07/09/11), and one on November 9, 2013 (09/11/13) but then it won't happen again for 92 years. And I sure won't be around to see it."

So what does Gordon suggest you do on "Odd Day"? It's a great day to do your odds 'n ends, give a friend a high-five or root for the odds-on-favourite, he says.

And fittingly, if Roger Federer wins the Wimbledon men's title today it will be his 15th Grand Slam title.

If these numerical oddities grab you, take a look at http://www.oddday.net/ and plunge into Ron Gordon's world.