CHICAGO — If one seven is lucky, three must be really lucky. That's the thinking behind the bonanza of weddings scheduled throughout the nation for July 7, 2007 — or 07/07/07.

"Couples are definitely superstitious," said Kathleen Murray, deputy editor of www.TheKnot.com, a wedding planning Web site. "I think they're looking for a great fun date, and 7-7-7 is very lucky."

Among the brides and grooms who have registered at the Web site, 655 couples are planning weddings on next July 7, compared with the 424 who have selected one of the other three Saturdays that month.

In northwest suburban Elgin, Ill., 23-year-old Terra Hubble, a child-care provider, says her fiance, Tim Fick, wanted a date he could easily remember in the future — either May 6 (05/06/07) or Sept. 8 (09/08/07) or July 7.

Hubble chose July 7, but said, "I didn't put together how popular the date was until I tried to book a hall." Luckily, she was planning an afternoon reception. "Evenings at wedding halls have been booked for two or three years," she says.