It's also a day when fans of the 1980s mockumentary film 'Spinal Tap' celebrate 'Nigel Tufnel Day.'
But Alexander Williams of Washington, D.C., decided to make this day extra-special by proposing to Dionne Savage, his unsuspecting girlfriend, at 11:11 a.m.
Williams met Savage at the Los Angeles International Airport American Airlines ticket counter more than two years ago, which is where he decided to drop the question.
He got a handful of friends to help him set things up, flew Savage in from Washington, D.C. and her mother in from Philadelphia, PA.
After some shock at the ticket counter, and a romantic serenade of "You Are So Beautiful," the clock finally struck 11:11 a.m.
"Will you marry me?" asked a hopeful Williams.
"Yes!" Savage exclaimed, prompting cheers from the crowd.
"We just talked about 11/11/11 today, and he didn't say anything about it, so this was a complete surprise because he didn't let on at all," Savage explained.
Now that Williams has set the bar high by getting engaged on 11/11/11, the next step is figuring out when the couple will get married. After all, 12/12/12 comes up next year.
"That's all on her now!" said Williams. "I'm ready! Just tell me what time to bring a suit and I'm good!"
After all the excitement, Williams concluded that 11/11/11 is not just a lucky day, but a perfect day.
"It's a perfect day now, because I got a yes," said Williams.