The signs say ``Always Open,'' but for the first time in 35 years, most of the 1,200 Denny's restaurants across the United States will close their doors for Christmas Day. Locking those doors is a different story. Some buildings have been without locks for decades because of the always-open policy. At others, the locks have never been used and the keys can't be found. The company is having to install locks at about 700 restaurants, said Joe Herrera, director of marketing at the company's southern California headquarters. The company decided to close this year so employees could have the day off. ``It will cost us about $5 million in sales,'' Herrera said. The chain's 60,000 employees were so grateful for the holiday that many sent cards and letters of appreciation to the offices, Herrera said. Employees received normal pay for Christmas Day. ``We just feel we spend 364 days a year taking care of other people's families; for one day a year we want to take care of our own,'' he said. Nobody wants to work on Christmas, he said, and it has been the top turnover day of the year, with some managers losing four or five employees. In Hollywood, the companywide closing solved manager Almaz Legesse's problem of choosing which employees of a Sunset Boulevard restaurant to give the day off. ``I had a big list. ... I was having a hard time,'' she said. The restaurant, which serves more than 1,700 Christmas customers, was awaiting a visit from a locksmith. ``We never had locks,'' Ms. Legesse said. ``After so many years of working Christmas every year it's real nice,'' said Lee Sevene, a manager at a Denny's near a turnpike in Portland, Me. ``People have always thanked us a lot for staying open,'' said Frances Bushman, manager of a Pismo Beach, Calif., Denny's. ``On the other hand they always felt sorry for our waitresses and cooks,'' she said. Ms. Bushman's Denny's has locks but she had to check to see if the keys fit. Christmases in the past have been about twice as busy as average days at Denny's, Herrera said. ``We have up to an hour wait sometimes on Christmas, and that's all day _ not just at midday,'' Herrera said. ``It actually starts on Christmas Eve, and just keeps going.'' The Christmas closing applied to 1,221 restaurants. The operators of 174 franchise restaurants were allowed to make their own decisions. Winifred Gibson, a manager at two Denny's franchise restaurants in Fresno, Calif., said they would remain open for the biggest day of the year. But she sympathized with the trouble of locking up a Denny's. ``Once I needed to lock the doors on my store. It was a major fiasco. It took us a day to find the keys,'' Ms. Gibson said. Christmas Day used to bring in mostly single people, couples with no children or elderly people with no family, she said. ``But not anymore. You have so many one-parent families.'' The three franchise Denny's in Anchorage, Alaska, and one in Fairbanks will be open, said Donna Flanagan, manager of an Anchorage restaurant. Ms. Flanagan expects to serve about 1,500 people on Christmas, which is second only to Mother's Day in bringing in customers.