For casino slot machines, the line 7-7-7, or "lucky sevens" is a winner.

But Kevin Martian and Tammy Liebersbach aren't gambling and they don't believe in luck.

The Mandan couple will marry on July 7 or 7-7-07.

"We are not superstitious at all," Martian said. "It has nothing to do with luck. It just kind of became our number."

Dozens of North Dakota couples will take advantage of the special date next month.

While Martian and Liebersbach chose July 7 for coincidental reasons, other couples chose the date for superstitious, "lucky" or religious reasons.

Many Christians consider seven to be a perfect number because the Bible puts a great deal of importance on it.

"Seven has a big significance in the Christian tradition," Good Shepherd Lutheran Church Pastor Dan Dornfeld said.

"It is a Godly number," Liebersbach said.

When Martian and Liebersbach were Mandan High School sweethearts, Martian's football jersey was number 77 and Liebersbach's volleyball jersey was number 7.

After celebrating anniversaries on the seventh day of each month for two and a half years, Martian proposed on Jan. 26, 2006.

He drove to Liebersbach's college in St. Joseph, Miss., where they walked to a bridge that overlooks a large pond. On the bridge it's quiet, but the area is surrounded by noisy streets, he said.

"I told her I wanted our relationship to be a calm place in the middle of a busy world, and I got down on a knee and asked her to marry me," he said.

The couple will marry in the afternoon of July 7 at Spirit of Life Church in Mandan, followed by a reception at the Doublewood Inn in Bismarck. They expect about 200 about guests.

Unlike Martian and Liebersbach, Joy Nelson and her fiance, Damon Jorgensen, both of Bismarck, chose to get married on 7-7-07 because it reminded them of "lucky sevens."

She isn't superstitious, but Nelson said she likes the date because it's very easy to remember.

Fittingly, Jorgensen and Nelson will wed at 7:07 p.m. on July 7.

Their evening wedding will be an outside ceremony near the Missouri River.

The ceremony will be relatively simple, with no flowers and no photographer, but they will have plenty of company. Nelson expects as many as 400 guests to attend.

When planning a wedding, most couples keep three or four dates in mind, Dawna Hagerott, communications manager for Good Shepherd Lutheran Church in Bismarck, said.

On July 7, Good Shepherd Lutheran Church in Bismarck also has a wedding scheduled, a couple has had the day reserved since June 30 of last year.

"Most of our weddings are booked about a year in advance because we only do one a day," she said.

If couples don't schedule early, it's often a challenge to coordinate open dates for churches or other venues with the availability of a photographer, florist and reception hall, she said.

So far, four couples have registered for July 7 marriage licenses in Morton County and about 10 have registered in Burleigh County. There will be six weddings inCass County that day.

Workers at Morton, Burleigh and Cass counties' clerks of court offices said it's hard to estimate how many couples will wed on July 7 because couples can register up to the day of their wedding.

May and June issues of Celebrate North Dakota, a weekly Bismarck Tribune publication that announces engagements, listed 14 July 7 weddings.

"We were thinking (July 7) is probably going to be a popular date," Martian said.