What sort of diary should I like mine to be? Something loose knit, and not slovenly, so elastic that it will embrace anything, solemn, slight or beautiful that comes into my mind. I should like it to resemble some deep old desk or capricious hold-all, in which one flings a mass of odds and ends without looking them through. -- from "The Diary," by Virginia Woolf

Virginia Woolf would have loved designer Karl Lagerfeld's diary. It's an optical log, filled with pictures of friends and snips of painting reproductions that could trigger dress designs. And, of course, a small Picasso alongside Paloma Picasso's new phone number in New York and their dinner date.

"Everything I like I cut out, so when I refer to the diary or am bored on the phone I can look at things I like," said Lagerfeld as he flipped through his book on a recent trip here. He was searching for the name of the boutique that makes his hats. It was easy to find -- he had clipped the ad from a newspaper.

The appointment diary, executive planner, agenda -- by whatever name it is known, it is for many a life support system. Says Paloma Picasso of the system she relies on, "The Filofax is great fun to play with, but if I lose it, I lose everything." And this is the time of year when new date books are being readied everywhere -- from the smallest paperback planners to the most elaborate, and expensive, agendas.

At one time noteworthy dates, addresses and even doctor appointments were recorded in the margins of the family Bible. Today the most popular diaries range from pocket-size books to weighty binders, with room for addresses, notes, recipes, even insurance forms. They reveal as much about the fine art of keeping track of appointments as about the people who carry them.

Back in her days at Georgetown University, United Nations Ambassador Jeane Kirkpatrick would tuck away bits of paper as reminders of appointments she had made. "They would stick to the bottom of my pockets and I could never find them when I needed them," she recalls.

She moved on to a progressively elaborate calendar when she moved to New York and the American Enterprise Institute, and now she consults mail and phone logs, as well as a daily schedule prepared by her secretaries.

"My agenda is a harbinger of the change in my life," she says. And there is no turning back. "I couldn't go back to pieces of paper. I'm not likely to go back to anything quite as unrecorded as I used to live. I don't see it in the near future. I'm likely to do a bunch of things, like speaking engagements, which have to be inscribed, and can't be lost."

Most modern appointment books are filled with far more than, well, appointments. Paloma Picasso used to sketch her jewelry designs on stiff Bristol pages added to her leather-bound diary, and recently all the sketches in her daily appointment calendar have been for the apartment she is decorating in New York.

Film producer John O'Brien records addresses and phone numbers with stick-on tabs in "my traveling desk," as he calls his refillable Italian leather-bound agenda. But directions to friends' houses, recipes and other notes are logged on permanent pages in the back. "If someone recommends a director or a screenwriter at dinner, I'd write it down on the day," he says. "It's not a system that anyone else could figure out."

Unlike most personal computers, agendas can be easily "reprogrammed," or adapted to suit the needs of the individual user. Next to addresses of appointments, Barbara Howar, New York correspondent of "Entertainment Tonight," lists cross streets and whether they run east or west -- to help taxi drivers. And after each interview she notes the color of the outfit she was wearing at the time. "If I had on a certain sweater when interviewing Paul Newman and the interview was to air close to a Dustin Hoffman interview, I try not to wear the same sweater," she explains. "It shouldn't look like I haven't changed my clothes in a month."

Howar also makes sure all her dates are posted in triplicate -- in desk calendars at home and in the office, as well as in the red leather zippered Carlos Falchi calendar she carries everywhere. "New York is so big you can't say, 'Call me later,' because by later you are doing 18 other things," she says. "This is a town where you strike while the appointment book is hot or the moment gets away from you.

"My agenda dictates my life. I'll only buy a purse that will accommodate it. I never thought I would grow up to be a slave to an appointment book." But she is. "Wherever I am, the book is."

Saks-Jandel vice president Val Cook once used a Gucci calendar about half the size of her current one. "And my life was half as full," she says. Today she carries a Smithson calendar in bright red so she can find it easily in the bottom of her handbag.

"I can't tell you what I can fit in this book," Cook says. On the crisp, blue pages she crams in the sizes of each family member, all insurance information, all current phone numbers, and all notes for calendars up to five years ahead, including vacations. Except for business appointments she must go to directly from home, all the references are personal. Several times a week she records her weight, although "when I'm feeling fat I don't get on the scale," she says.

Rather than making notes on an agenda, Lady Marjory Wright, wife of the British ambassador, keeps "nasty little blue pads" everywhere in the embassy residence and jots things down as she thinks of them. "If I think of something in the shower, I would surely forget it between the bathroom and the desk," Wright says. She then turns them over to her secretary, who logs them in her engagement calendar.

"If I kept the diary myself it would be work for two people," she says. "To keep my diary is a full-time job." Indeed, even friends who want to make a date are referred to her secretary, who also keeps "a roller thing, listing who has come to dinner and what they have eaten."

Personal hieroglyphics often brighten the agendas typed by secretaries. Architect Hugh Jacobsen draws black ties next to the listings of formal dinners on the computer printouts prepared for him three times a day, and in the margin of one recent agenda he sketched a sofa he had suggested to a client.

White House Deputy Chief of Staff Michael Deaver also relies on a computer printout, prepared a month in advance and geared to the president's schedule, which appears on the same page. Only three others besides himself see Deaver's daily schedule. His own copy is annotated by his secretary, Donna Blume, with such remarks as "tux needed."

Deaver's wife, Carolyn, who functioned comfortably on a page per month before coming to Washington, now easily fills up her "Week-at-a-Glance" book. She writes phone numbers on those pages, but no frivolous notations. "It is too delicate a document for doodles," she says.

For Robin Weir, Nancy Reagan's hairdresser, the Gucci day book (bought after he noticed Julius Bengtsson, the first lady's other hairdresser, carrying one) is not only a social register of clients but a business record. Just this week he referred to his four-year-old datebook to figure out how much extra help he would need for the upcoming inauguration. "I had thought of offering clients a limousine ride at that time," he says. "But when I counted up 130 clients a day, I realized I couldn't afford it."

This year friends of Evangeline Bruce persuaded her to abandon her French agenda and switch to the Filofax, the quintessential organizer. "I've been wedded to the same French one for 30 years. I'm trying to wean myself this year," she says. "Now I have one foot in and one foot out of my old one. I will probably keep all five toes in the Filofax."

Oatsie Charles is one Washingtonian who never removes a name from an old address list, even if the person has died. "It's my memento mori -- it makes me think kind thoughts of my friends who have passed away," she says.

Transferring information into a new book is time-consuming, "but a lot of fun," says Paloma Picasso, who is also switching to the Filofax. She bought one four months ago but decided to respect the book's starting date rather than jump in midyear. Hers is in black ostrich with white, gray, pink and yellow pages, many with fine graph lines, and onionskin. The heavyweight Bristol pages are her own variation on the system.

Ronald Kaiser, president of British Filofax System, figures that at least 75,000 people in the United States have become hooked on Filofax since it was first sold here two years ago, and many more Americans have purchased them in London. Steven Spielberg and Diane Keaton own this high state of agenda art, and so do all the Ford models -- who got them from Eileen Ford as Christmas gifts.

The highly functional system was started in London in 1920 by a printer who refined an existing system. Kaiser likes to tell the story of the army captain who showed up with a Filofax with a hole in the front, claiming the book he carried in his pocket had saved his life. And according to Kaiser, Filofax was used as the data book for the British climbing expedition on Mount Everest.

There are now more than 125 different insert page options in 12 colors, including hotel lists (with blanks for names of concierges and favorite rooms), restaurants (including favorite dishes and the name of the sommelier), city maps and home entertainment (including guests, drink preferences, caterer, florist, even what the hostess wore, with a dinner seating plan on the reverse side).

Kaiser is developing an expense listing to reflect any new tax laws and specialized inserts for the professions. In fact, Dr. T. Forst Dagi, a neurosurgeon at Georgetown University, is working up patient record forms for doctors to use in conjunction with the Filofax. "Nothing original," says Dagi, who saw similar systems used by doctors in England.

Judith (Miss Manners) Martin says the Filofax not only keeps her organized, it keeps her polite. "If you are kept waiting, you might get angry, except that this offers perpetual amusement. I might write a speech or plan a party in my book." The system also offers a party planner that leaves room for personal and professional data on guests, but that horrifies Martin.

Eventually there will be Filofax covers in buffalo and elephant, though a $600 crocodile version for sale in London can't be sold in this country because the skin is considered endangered in California, where Kaiser, the American licensee, is based. Made in the same factory in England that makes Rolls-Royce accessories, the covers are guaranteed for five years.

Filofax does not include the gold or silver metal pen or pencil that's tucked into many of the classic European styles like Hermes -- but that doesn't matter, since those pens rarely last the life of the diary. Jewelry designer Kenneth Jay Lane has held on to the original pencil that came with his Hermes diary, but can't keep the lead that goes into it. No matter -- his small black leather book is the perfect size for credit cards and a "Picadent, which I can't live without."

The diary provides Lane with more information than he needs ("I know all the saints days"), but since it accommodates only three months at a time, he periodically gets into a jam. "The end of September is always terrible for me," he says. "I get very screwed up on dates for October, because that is when you need a new filler." He ends up squeezing all the October dates made in September onto one page, which "guarantees that I miss at least two engagements."

"It drives me nuts," he says, "but I wouldn't be without it for the world."

For the addicted, the biggest fear is losing the notebook. When he's traveling, Lagerfeld carries in each suitcase photocopies of his notebooks. Sharon White, an interior designer who has been working on a hotel in the Whitsunday Islands in the Great Barrier Reef, was prepared to fly back across Australia when she realized she'd left her Filofax behind. "It had everything in it -- my daily notes, cards, sources. I was ready to slit my throat," she says. The book was found in Brisbane and forwarded to her in Sydney -- where she was waiting at the airport.

Judith Martin once left her Filofax in a taxi. "I didn't want to go on living," she says. "I felt I could re-create my life, but it wasn't worth the trouble." She now travels with a scaled-down version -- just a week of appointments -- and leaves the complete Filofax at home.

The handsome Ghurka daily agenda, made in Norwalk, Conn., carries a registered number so the owner can be traced if a lost book is found. Marley Hogdon, who devised the book, says he knows of only one owner who was not happy to get his datebook back. "That was when the FBI came across one in a drug bust," he says.