Nearly 8,100 couples have so far booked to obtain a wedding licence on August eight, the opening day of Beijing Olympics and a number considered lucky by the Chinese.
More than 9,000 couples are expected to tie the wedding knot on the day.
Beijing marriage registry authority would remain open over the two coming weekends July 19-20 and July 26-27 for couples who want to book, an official said.
"Considering many people have no time to apply for the date in person on workdays, we decided to give up the weekend holiday," Li Ziwei, head of the marriage registry office of Beijing Municipal Civil Affairs Bureau, was quoted as saying by Xinhua news agency.
Chinese link eight with good fortune and feel the opening date of Beijing Olympics adds a new meaning.
Anticipating marriage registration boom on August eight, Beijing Municipal Civil Affairs Bureau opened a marriage booking service from June 20 to August 5.
"With the booking form, couples will get their marriage certificates on Aug. 8 within one or two minutes," Li said. "But usually, it takes about 10 minutes to fulfil the registration."
From June 20 till Tuesday last, 6,100 couples had booked the date at the marriage register offices in Beijing, and more than 2,000 others had done it online.