A Michigan sixth-grader will put aside her nerves and get her ears pierced on her 12th birthday. Two law-enforcement officials will exchange wedding vows at 12:12 p.m. in Pittsburgh’s federal courthouse. And gamblers can take advantage of promotions some casinos are using to lure in patrons who want to test their luck.

With a once-a-century date arriving today, some people across the United Stated are betting on good fortune for 12-12-12.

In New England, Foxwoods Resort Casino in Connecticut will offer $12 in free slots play to rewards cards members who sink $12 into the slots.

A southwestern Michigan casino is also betting that 12-12-12 is going to be a lucky day for opening its new hotel. A ribbon-cutting is planned for 12:12 p.m. today for the eight-story, 242-room hotel at FireKeepers Casino near Battle Creek.

Hours later, Anna Gandy, of Battle Creek, Mich., will head to the Lakeview Square Mall after school lets out. She realized last year that she would turn 12 on 12-12-12, her father, Bryan Gandy, said Tuesday. But between her sports team commitments and nerves, Anna decided to wait until today to get her ears pierced.

"She’s been looking forward to it for a year," her dad said of the special birthday. "She obviously likes the number 12."

Fans of some of music’s biggest names will feel lucky to see them share a stage today in New York’s Madison Square Garden. The charity show for Superstorm Sandy victims has been dubbed the "12-12-12" concert and will include Bruce Springsteen and the E Street Band, Paul McCartney, the Rolling Stones, the Who, Eric Clapton, Billy Joel, Kanye West, Alicia Keys and Bon Jovi.

For pro football fans, today’s date also will carry special meaning.

Green Bay Packers quarterback Aaron Rodgers wears No. 12, and the Wisconsin state Legislature has designated the day Aaron Rodgers Day in honor of the Super Bowl winner and last year’s MVP. Some businesses are encouraging employees to wear Rodgers jerseys and make $12 donations to a charity fund.

And in honor of New England Patriots quarterback Tom Brady, who also wears No. 12, his team is planning a series of events, offering free admittance to its interactive museum in the 12 o’clock hour and discounts at its shop — 12 percent off, naturally. The team’s Facebook post had more than 12,000 likes in its first hour.

According to Vicki MacKinnon, who practices numerology, the study of the occult significance of numbers, today’s date represents two energies merging, including masculine and feminine energies.

MacKinnon, of Calgary, Alberta, author of "Please Take a Number: Numerology for Real Life and Everyday Success," said Tuesday that those kinds of energy are good news for couples planning to marry on 12-12-12.

Among them are Assistant U.S. Attorney Amy Johnson and Deputy U.S. Marshal Brian Allen. A federal judge in Pittsburgh will marry the couple at 12:12 p.m. as they exchange 12-word vows.

Johnson, 34, said the couple had been planning a small ceremony until word leaked out of their numerically unusual plans.

"A lot of people started thinking it was interesting and intriguing that we chose this day. Prior to that it was going to be a very small venture, but it’s kind of spiraled into something," Johnson said.

Officials at the Milwaukee County Courthouse also expect the hallways to be bustling with brides and grooms. At least 27 couples are getting hitched on the 12th day of the 12th month of 2012, compared with about six on a typical Wednesday.

In Las Vegas, MGM Resorts spokeswoman Yvette Monet says most of the six casino wedding chapels the company has along the strip are close to fully booked for today.

But weddings aside, MacKinnon said, her reading of the date shows good fortune can come to anyone who demonstrates good intentions in whatever they do on 12-12-12.

"I just believe that as long as we conduct our lives with the highest intentions for ourselves and others, we can make very good use of the energy tomorrow for manifestation of what we want to bring into our lives," MacKinnon said.

Murphy reported from Boston. Contributing to this report were Associated Press writers Joe Mandak in Pittsburgh, Dinesh Ramde and Gretchen Ehlke in Milwaukee, David Runk in Detroit, and Hannah Dreier in Las Vegas.