LAS VEGAS — On a day when thousands of people were convinced the calendar made this gambling town the luckiest place to wed on the luckiest day of the century, this might have been the quintessential 7-7-7 wedding: The groom wore green slippers with a beer bottle opener built into the sole. The tattooed bride with blue toenails and smeared mascara arrived at 2 a.m., hyperventilating and crying, the rings forgotten somewhere.

At the end of a brisk ceremony at the Graceland Chapel, Elvis crooned "Viva Las Vegas" while the couple smooched. And if all that wasn't spectacle enough, a relative in a tuxedo T-shirt snapped pictures — even when the newlyweds toppled from a bench to the ground, a mess of legs and tangled tulle and satin.

"It was either this or the Caribbean," said groom Jon Andreano, 29, of Denver. "But there's nothing cooler than getting married by Elvis. This is Vegas. It's the way it should be."

Whether it was romance, superstition or luck — or that extra gimmick needed to drag one's partner down the aisle — a record number of couples tied the knot around the world yesterday, taking advantage of a once-in-a-century calendar convergence that gave them an anniversary date impossible to forget: 07-07-07. And nowhere were more couples lining up than in Las Vegas, where the "I dos" began at the stroke of midnight and continued nonstop at virtually every casino, hotel and chapel in town.

Every limo was booked; every Elvis on the job. Vegas residents David Heilman and Charlene Jimenez literally took the plunge, getting married underwater in a Silverton Casino aquarium teeming with sharks, 4,000 tropical fish and two ring-bearing mermaids.

Heather Grant of Henderson married Wayne Gray on a pirate ship at Treasure Island. "Tacky," she said, was the theme of their nuptials.

"We are knee-deep in weddings," said Charlotte Richards, owner of the Little White Wedding Chapel, which held more than 500 weddings, including some for couples who didn't even have to exit their car.

In Vegas, the triple-7 date is considered extra lucky because three sevens add up to 21, a winning hand in blackjack. Three sevens on a slot machine signals a jackpot. And there are the Seven Wonders of the World. God rested on the seventh day. Buddha walked seven steps at birth. And according to Islam, there are seven heavens.

Clerks at the Clark County Marriage Bureau called it their "busiest day ever." On Friday, they issued 1,774 marriage licenses; previous records stood at about 1,000. By midday yesterday, they had issued more than 600.

Despite the kitsch and extravaganza, there were also many tender moments.

Las Vegas residents Annie O'Gwin, 53, and Marc Higdon, 54, drove up to the Little White Wedding Chapel's Tunnel of Love in a rented silver Prowler. After 20 years together, they finally decided to tie the knot.

"This was one of those opportunities to seal it," Higdon said. "We've both been married before. They failed. So we figured, lucky numbers."