Couples across New York are taking advantage of Wednesday's once-in-a-lifetime date - 09/09/09 - to tie the knot.

When Justin Allsopp, a 29-year-old child advocate, proposed to Barbara Fitzgerald, she already had the date in mind.

"Nine is my lucky number," Fitzgerald, 28, an attorney, explained.

The two also discovered that the Irish say the luckiest day to get married is Wednesday.

"I did some research and saw that there were two or three days that every culture agrees on as lucky days," said Fitzgerald, who will wed in Sandy Hook, N.J., near her and Allsopp's hometown.

"Nine, nine, nine is just lucky all around!"

The quirk of the calendar, which won't roll around again until September 2109, is considered especially auspicious for Chinese brides because the Mandarin word for "nine" sounds like the word for "long-lasting."

As one bride-to-be, Silin Trenh, 28, explained, "We picked [the date] because the Chinese meaning of the number nine is longevity."

Trenh, an office manager, and her fiancé, Thanh Von, a 31-year-old lab tech, who both split their time between Manhattan and Boston and are both Chinese-American, are planning a small ceremony at City Hall with their close friends and family, followed by a celebration at City Hall Restaurant.

The luck of nine isn't just in the sound of the word.

Nicole Lin and Joe Hill, 40, who both work with antiquities, explained that nine, because it is the highest single digit number, is associated with the Emperor of China and so will add an extra touch of class to their wedding day.

"We struck upon the date of 09-09-09 a little late in the game," said Hill, of Brooklyn, admitting the couple only picked the day about five months ago.

Thankfully, the last-minute wedding will work out.

The two chose to incorporate Lin's heritage - with an updated twist.

Though traditionally, the bride serves the groom's parents, Hill and Lin, who lives in Queens, agreed to serve each other's parents as a sign of unity. "We're serving tea to our elders," Hill said. Just to add an extra twist to the festivities at their Riverside Church wedding, the bride, who is in her 30s, will walk down the aisle in an antique Edwardian wedding gown sewn in 1909.

(Agencies)