INSTINCTIVELY you pity them, the unfortunate few who must go to work on the one day of the year when staying home is all but a national mandate.

How sad, you think: While you're loafing with your family or destuffing your Christmas stocking, those poor souls are desperately trying to shrug off the blahs and shift into an industrious mode.

How stark are the contrasting images that dance in your head: You reclining in your easy chair . . . they hunching over computer keyboards. You passing a gift to your sweetie . . . they passing tickets through box-office windows. You taking another helping of cookies and eggnog . . . they taking dinner orders from a party of nine.

Yep, it's truly lamentable that not everybody gets a daylong breather on Dec. 25. But before you start feeling too sorry for Christmas workers in general, you should understand that a lot of them -- particularly those ones involved in entertainment -- don't necessarily despair about their yuletide toil. Listen:

"Everybody says to me, 'Why do you work Christmas?' " says Donna Marcopulos, a bartender at the Willard Inter-Continental Hotel's Round Robin Bar. "Not only is it a lot of fun and I have a good time, I also make a lot of money {in tips}. I don't know if it's because people feel sorry for you because you're working Christmas, or what. But it's just a fun day. I wear a Santa Claus hat and these Christmas earrings that light up. I just do a lot of fun things."

Keith Shuman, general manager of Mrs. Simpson's restaurant in Northwest professes to like working not only Dec. 25 but also Christmas Eve and New Year's Eve.

"It's because of the mood of the people," he explains. "It's very festive. It's busy. Everyone's up, including the wait staff. And it's more like a social gathering than independent customers coming in. We get a lot of neighorhood people who come in every Christmas, every New Year's, and it's a pleasure to see them."

Even people who'd prefer not to work on Christmas, but plan to do so this year, typically can find something redemptive about the experience.

Emory Greene, a technician at PBS's Alexandria headquarters, says it feels good to know he's doing his part to bring "Sesame Street" (among other shows) to Americans on Christmas. Also, he knows that by working he'll possibly improve some colleague's family's holiday.

"If I didn't work, maybe one of the younger fellas with children would have to," says Greene, 60, whose youngest child is 13. "It's a matter of being responsible."

A matter, too, of economics: Greene will be paid twice his usual rate for working Tuesday.

Actor Jaston Williams, who will appear in "A Tuna Christmas" at the Kennedy Center, enunciates a show-must-go-on attitude similar to Greene's.

"There are a lot of people at Christmas that are away from home that really need to be entertained," says Williams, who co-wrote the comedy with Joe Sears and Ed Howard. "So if we can provide them some entertainment, that'll be fine. I'd rather have it off, but I don't, so we're gonna make the most of it."

Instinctively you pity them, but all you really ought to do for the people who entertain you on Christmas is pay them a little extra attention this week. Ask them for their stories, as we did with the six people sketched on these pages. Listen to what they say about arranging celebration around a stint of labor, about making the most of the day.

Maybe the things you hear will help you wholly enjoy your own holiday, in case you've fallen into the habit of doing otherwise.

A COLONIAL CHRISTMAS

Sharon Nicholson's oldest son, a real clown, will be in Florida at Christmastime, training for a circus. But her other four kids, ranging in age from 13 to 25, will be home. And the fact that mom is working Tuesday morning will give the four an opportunity to do some clowning of their own at Mount Vernon.

"When they get up, they're gonna come up here and visit me," says Nicholson, a "historic interpreter" -- tour guide, if you will -- at George Washington's historic home. "If we're real busy, they'll go through and say hi. If we're not busy, they'll stay and talk. They might come through and ask every dumb question they can think of. They know the ones that drive us nuts."

Example: Did George Washington have an affair with Sally Fairfax?

Answer? "Absolutely not," declares Nicholson. Fairfax was a close friend of the first president, she says, but never a sex partner.

Also, the kids may ask what Washington really died of, implying, as mischievous visitors are wont to, that venereal disease felled him. In fact, the cause of death was more mundane: a throat infection.

The privately operated Mount Vernon is one of the few tourist attractions kept open on Christmas. Spokeswoman Ann Rauscher says the custom goes back to the Hoover administration.

"Mount Vernon is a national shrine," Rauscher says, "and it was felt that all Americans should have the opportunity to visit here. And if they were only in the area for one day and Mount Vernon was closed, it would be horrible."

Enlisting historic interpreters for yuletide duty is no problem. A full day's pay is offered for half a day's work, and besides, staffers are given lots of advance warning.

"When you hire on at Mount Vernon they are very specific about one thing: You're expected to work either Thanksgiving Day, Christmas Eve or Christmas Day," says Nicholson, who was hired in February 1989. "There are no ifs, ands or buts. Everybody has to take their turn."

Upwards of 2,000 visitors typically show up at Mount Vernon on Dec. 25, making it two or three times busier than the average winter day. This year, for the first time, guests will get to gawk at a fake-food exhibit -- a replicated holiday feast -- in the mansion's main dining room. The exhibit's centerpiece is a Christmas pie.

Escorting a visitor through the mansion one recent morning, Nicholson pauses near the dining room's 12-foot-long trestle table and describes the pie's contents: "A turkey stuffed with a goose stuffed with a hen or a fowl of some kind, stuffed with a partridge stuffed with a pigeon. It's surrounded by wild game such as rabbit or hare and seasoned with nutmeg and mace. It's put into this heavy crust and baked. After it's baked, a hole would be opened in the top of the crust and they would pour in four pounds of clarified butter, and that would preserve it. And then they would eat this thing for up to two weeks."

In another room, Nicholson is asked why there are pine branches hung about the house, but no Christmas tree.

"Christmas trees, stockings, all those things that we associate with Christmas, are Victorian," she says. "And probably the first Christmas tree came to America around 1830 with the German immigrants. So the Washingtons would have just had the greenery."

Four hours of such discourse won't by any means ruin Nicholson's holiday. At quitting time Tuesday, she says, she'll still have plenty of zing left for family revelry -- although, having repeated that pie recipe all morning, she may not feel like taking a big supper.

DINNER WITH MRS. SIMPSON

Restaurant patrons not only tip better on Christmas Day, Keith Shuman has observed, they also become unusually docile.

"We wouldn't abuse our guests, but if we did, I don't think they would stand up and have a fit on that day," says Shuman, general manager of Mrs. Simpson's restaurant in Cleveland Park. "Any other day, maybe."

Lest his listener get the wrong idea, Shuman adds, "We don't abuse anybody."

Until three years ago, Mrs. Simpson's always closed on the big holidays. "The reason we decided to open was that we consider ourself now as a neighborhood restaurant," Shuman says, "and we feel we should be available to the people that live around here."

To accommodate its patrons, who eat supper earlier than usual on Christmas, Mrs. Simpson's will open at 4 Tuesday instead of the usual 5:30. Shuman will work from 3:30 till 9 or 9:30. The job won't interfere much with his personal Christmas duties -- "rushing around a little bit to visit friends" -- which he'll attend to in the morning.

Coming from a family of restaurateurs, Shuman takes holiday work in stride.

"I'd say I started working on Christmas way back when I was in high school," he says. As general manager, he performs a variety of tasks at Mrs. Simpson's: "overseeing the floor staff, the kitchen, food quality, scheduling, staffing, and keeping an eye on all aspects of the place for the owner, Jason Wolin."

How can one guy do all that? Easy, Shuman says. "It's a very small restaurant, and the staff we have working is a very good staff. It's kind of a family-oriented feeling."

And remember, folks, they don't abuse their guests at Mrs. Simpson's. Even on Christmas.

BLOOD AND HOLLY

Jaston Williams makes Christmas with his extended family, a Texas clan, sound like a powerful argument for working overtime on Dec. 25. "Blood and holly" is the family nickname for the affair.

"At our house you just never know what will happen," says the actor/playwright in a phone call from Austin, Tex. "It's your basic traditional Christmas: We eat, the children tear the tree down and we go home. You know? And hope that no in-laws start a fight."

If any in-laws tangle this year, Williams won't be around to savor the drama. On Christmas, he and writing/acting partner Joe Sears will be one week into a five-week run at the Kennedy Center. Their play, "A Tuna Christmas," opened Dec. 18.

"In a way I really don't want to be working Christmas Day," Williams says, "and in another way I'm just so grateful to have the work. And to be at the Kennedy Center is a real honor, so I can't get too upset about it."

"A Tuna Christmas," like its predecessor "Greater Tuna," is set in the fictional rural town of Tuna, Tex.; it features 22 characters, all of whom are played by either Williams or Sears. Costume changes are frequent, swift and invisible to the audience.

"We call it controlled schizophrenia," Williams says. "It takes a lot out of you, so you really have to rest."

Williams plans to attend a late-morning Christmas service at the National Cathedral. From there he'll head for a dinner buffet at the Willard, which will be attended by the play's entire crew. "And then I will go to bed and try to sleep all of that off. And then I'll go to work."

Christmas Eve falls on a Monday, the regular day off for theater folk. Though it would be possible to make a roundtrip dash to Texas, early Monday to midday Tuesday, Williams says he and Sears never considered doing that.

"Joe and I don't work with understudies," he explains, "so if we're late getting back, we're in big trouble."

FIFTEEN HOURS BY HERSELF

When you ask, she frankly, flatly tells you she's an excellent bartender. And then Donna Marcopulos, mixologist at the Willard's Round Robin Bar, unhesitantly names the two foremost qualities that confer excellence in her calling:

"Knowing your drinks. And getting to know your regulars, your clientele. As soon as you see them walk in the door, have their drinks already sitting at the bar, which I do for all my regulars."

At Christmas time, Marcopulos's regulars not only find their regular drinks waiting at the bar, they find special eats too. Cakes, cookies, candy -- "I bake everything," says Marcopulos, who has worked at the Round Robin since the hotel's grand reopening in 1986.

"I don't get anything from the Willard. I do my own baking and I have the whole bar decorated. I bring everything. And everybody looks forward to it."

Marcopulos knows customers look forward to it because they start calling in mid-December to see if she'll be doing her usual Christmas shift.

Normally, two bartenders work in the evening at the Round Robin. So Marcopulos will get some help on Christmas?

"No, no, no," she says, seeming almost offended by the notion. "Just me. I'm the only one. It's my day, fifteen hours by myself. Every Christmas and every New Year's."

You needn't be one of Marcopulos's regulars to enjoy yourself at the bar. One of her other excellent skills is making you feel right at home on your first visit.

Nancy Sisson, a regular from Annandale, says, "Donna introduces everyone. 'Nancy, this is Bob, he's a regular here.' Or, 'This is Joe. Joe comes into town every two weeks.' Before you know it, you walk in there and you just know everyone."

But we're not talking meat market here -- hey, this is the Willard.

"I feel very safe going there," Sisson continues. "There's nothing but gentlemen. I've never run into a problem where anyone was rude to me or anything of that nature. I feel I can sit there and have a drink and have some conversation without being hit on."

Len Lester, another regular, says of the bar, which is decorated with dozens of portraits of famous Washingtonians, "I sometimes think of it as a sort of sophisticated Cheers."

Marcopulos's one-woman yuleathon started out humbly in 1986.

"Nobody wanted to work Christmas because most of the guys that I work with have families, and the other {female bartender} has children," Marcopulos says. "And I'm single. And I just thought, I'll go ahead and work. Then after the first year I had so much fun that I volunteered. Now I start out, back in October I'll say {to my boss}, 'Are you doing the Christmas schedule? Remember, I want to work by myself.' "

Nobody fights her for the privilege.

Spending Christmas Eve with her mother and three siblings and various nieces and nephews, Marcopulos finds herself itching to get to work by late Christmas morning. She believes a lot of people feel Christmased-out after the presents have been opened and the stockings despoiled. They're hungry for the kinds of company and kicks they can't get at home.

"This is why they come here," she says, sitting at a table near the fine round bar in the middle of a Monday-afternoon break. "I'll see some of them and say, 'I can't believe you're here.' And they say, 'We got bored. The presents were opened, and we finished dinner and were stuffed, and we thought, "Let's go visit Donna." ' And they do."

And before their bottoms meet the bar stools, Donna's got their drinks ready for them. And the day's merriness commences anew.

PHONING IT IN

It has been seven years since Judy Grothe last spent Christmas with her family, in St. Charles, Mo. For her this is not a completely bad thing.

"Part of me almost feels it's good luck to work on Christmas," says Grothe, a McLean resident who's stage manager for "Shear Madness," the long-running Kennedy Center comedy. "Theater jobs come and go, and somehow I've been working every Christmas away from home for the last seven years, and on the road for the last five years. It's like, 'Oh good, last year I was working, this year I'm working -- it's going good, the career's working.' "

Which is not to say Grothe ignores her faraway loved ones on Christmas. Indeed, the family has developed an effective, enjoyable routine: "We send presents ahead of time, and promise we won't open them. And then we call when we're opening them so we can at least get an audio reaction to what we bought. 'Oh, that's perfect!' Or, 'It's not perfect, it doesn't fit!' "

It's not the same as being there, she says, "but it's close."

On Tuesday, as usual, Grothe will call her parents at noon. Afterward she'll linger in her apartment, playing Christmas carols to "stay in the mood and stay happy."

"Shear Madness" starts at 8, and Grothe will arrive at the theater by 6 to open up.

"I'm in charge of making sure all the supplies are there for the show. We go through a lot of shaving cream and barber supplies, since the show is about a hair styling salon."

Grothe supervises the crew, "which is the costume crew and the stage crew -- the carpenters and the property people and the sound people and the light people. And when I get here, we make sure that the set's up properly, the props and costumes are out properly."

At 7:30 sharp, Grothe will open the house and let the audience in. During the show she'll call all the cues for lights, sounds and special effects. "And then at the end of the show I'll take down everything that I put up and I'll lock it all up. Then I'll wait till everybody's out and lock all the doors behind me."

First person in, last one out.

Christmas audiences are generally mellow, Grothe says. "They're not as raucous as a Friday or Saturday night crowd. It's not to say they're not as good -- it's just a different feel. And certainly better dressed, since they all have new clothes."

The cast and crew will also be in an uncommon mood. "Christmas night is always a special show because you're together when it's normally a holiday that people spend with their families. I don't know, maybe that makes you closer as a working group. Theater is unique in that way. You get very close to people you work with in a show."

Not surprisingly, all of Grothe's recent Christmas memories are job-related. Two years ago, she was in Schenectady, N.Y., working on "Cats." There was deep snow on the ground, and the show people wondered if they'd have an audience. They had a big one.

Last year Grothe was with "Cats" in New Orleans. She savors the memory of defying the hotel maids there by stringing up Christmas lights in her room. She recalls, too, how weird it felt to celebrate the big day in the Big Easy.

"People can drink on the streets and, you know, they were buying beers on their way to midnight mass," Grothe says. "It was all very strange. It was warm and you're thinking, 'This doesn't feel like Christmas.' "

But back in her hotel room were gifts from home and a telephone. So a proper Christmas feeling was, as usual, only a noontime call away.

IMPORTANT TREE-SIDE PRESENCE

"Excuse me, sir, do you know if there's any way to get a grate off the street near the Ellipse?"

The woman had just visited the National Christmas Tree, across E Street from the White House's south lawn. Unlocking her car, she had dropped her keys through a wide-gapped grate. Cold, embarrassed, getting desperate, she had done what most people do when they need assistance in or near a national park. She'd sought help from a ranger.

Sam Swersky, the ranger she found, recalls that the keys had come to rest only a few feet under the grate. "We wound up getting a clothes hanger from the information kiosk on the Ellipse. It took us 10 minutes to get the keys."

That happened last Christmas, a workday on which Swersky also pushed a stalled car off E Street, picked up dozens of pieces of litter, answered hundreds of questions and may have prevented the accidental charring of one or more citizens.

The charring threatened to occur when people started throwing crumpled religious pamphlets into the yule log fire that's part of the annual Christmas Pageant of Peace at the Ellipse. (The two trash cans at the site were hard to see.)

"Half a dozen people were distributing the pamphlets at the two main entrances to the Pageant," says the soft-spoken, bespectacled Swersky. "It's certainly not the government's place to interfere with the dissemination of religious materials, but it was causing problems for us."

The yule fire was so hot, he says, that the pamphlets were bursting into flame even before touching the logs.

"Ash was coming up over the crowd," the ranger says. "This was a real safety concern."

Mindful of the pamphleteers' rights, Swersky suggested that they distribute their handbills only to people who were exiting the pageant.

"They didn't mind," he says, "and we had no more problems."

A ranger since 1988, Swersky is presently assigned to Glen Echo Park in Maryland. Glen Echo is closed on Christmas, so he habitually volunteers to work Dec. 24 and 25 at the Ellipse, where he was stationed until mid-1989.

Hardly any rangers volunteered to work Christmas the first year Swersky was on the job, he says.

"And I thought it would be nice to work that day because I'm Jewish. And it would allow the other rangers to be home with their families."

Last year Swersky worked 4 till midnight on Dec. 24 and noon till midnight on Dec. 25; this year's hours will be similar. On Christmas Day, some 20,000 visitors are expected at the pageant, which incorporates the big Christmas tree, 57 smaller trees representing U.S. states and territories, a squad of caged reindeer and the aforementioned yule log fire. Holiday music plays over a loudspeaker between live choral performances.

"It's a very leisurely stroll for these thousands of people who are in such good cheer," Swersky says. "You can't help but love being in small part responsible for this time they're having."