Some July 7 brides say they believe they are being forced to pay a premium for services that wouldn’t cost as much on any other Saturday this summer. “Once we told them we were getting married on July 7, the tone changed,” said Esther Marius, from Brockton, Mass. After calling 20 limousine companies, only to find that they were all committed to other weddings on July 7, she ended up paying $400 more than she had planned to secure the 24-passenger stretch limo she wanted to arrive in on her wedding day.

If it weren’t for the deposit she has already paid to the wedding hall, Ms. Marius said she would consider changing the date. “It’s gotten to a point where we said if someone wants to buy the date, we’ll sell it,” she said. “We could get married the month before or the month after.”

Others aren’t so flexible. Jennifer McVay, social and travel sales manager at the Sagamore resort in Lake George, N.Y., which is holding four weddings that day, said that at least three brides demanded to be put on a waiting list in case any of the weddings were called off. One has even checked back to see if any of the other couples had decided to break up.

“They’re just desperate for that date,” Ms. McVay said. “I really appreciate it’s such a big day and it’s really special — but I was surprised they weren’t as willing to move to another date.” She said several couples had already turned down her offer of July 6, which has plenty of openings.

Image Michelle ONeill says the Ritz-Carlton Lake Las Vegas gets three to six calls a week requesting July 7 weddings. Credit... Hiroko Masuike for The New York Times

Among those who have had to scramble to find a place for their wedding on the 7th are Lisl Kludzuweit, 33, and her fiancé, Artie Jones, 35, both from Philadelphia. After calling roughly half a dozen places only to find out that other couples had already taken them, Ms. Kludzuweit booked the Camden Windward House in Camden, Me., sight unseen. (Still to be found: a photographer who is free that day.)

Ms. Kludzuweit said it was important to her to secure this specific day for her wedding, despite the hassles. The couple picked July 7 after finding out that a tumor removed from Ms. Kludzuweit’s abdomen last year was benign. “For us it was symbolic,” said Ms. Kludzuweit. “It just felt so lucky.”