IF YOU were a Babylonian cobbler 3,000 years ago, you didn't have a birthday. Kings, queens and other nattering nabobs had birthdays -- as well as royal astronomers to tell them what day they fell on.
For ordinary folk, birthday celebrations didn't exist. Nor did the birthdays themselves. In fact, most days were pretty much alike. Some were dustier than others; some were hotter. Sometimes it even rained. On occasion, the brighter stars were in one part of the sky; on other occasions, they were in another.
Things were much simpler then -- sandier, but simpler.
Back then, you didn't have bookstores piled to the ceiling with calendars as one of the season's hottest gift items. And you didn't have to worry what statement your gift calendar was making about yourself or your gift's recipient. (If, for instance, you give your hugely overweight sister a Weight Watchers calendar, there's every possibility that she'll carefully contrive a moment, later on, to dump a tray full of hot Christmas cookies on your hair.)
So the trick, as with all gifts, is knowing what the gift says about you and your giftee before you do your buying and wrapping. Some of those in 1991's splendid crop of calendars:
For Sexist Oglers and Those Who Want to Make Sport of Sexist Oglers: The Sports Illustrated Swimsuit Calendar, by photographer Robert Huntzinger (Little, Brown, $10.95), is the way these things are done these days in places outside the boiler room. Even so, to commemorate August, Elle McPherson wears a suit guaranteed to cause a riot at Sherkston or any other beach. The diary engagement book version (Little, Brown, $12.95) makes it all available for desk tops.
Those who can't resist pointing out the perennial infantilism of such voyeuristic male high jinks should know about the 1991 Bloom County Swimsuit Calendar (Little, Brown, $8.95), even though cartoonist Berke Breathed's Miss August is no riot-starter.
For Literary Types and Not-So-Literary Types: Caitlin and John Matthews' Arthurian Book of Days (Macmillan, $19.95) tells you, for instance, that on Oct. 24, "Mordred, Arthur's bastard son, whom he had once tried to have killed, but to whom he had given cautious but increasing trust, had declared Arthur and Gawain dead." Those addicted to late nights with a good mystery might like William Malloy's Mystery Book of Days (Mysterious Press, $15.95), the place to turn to find out that on April 2, 1920, Jack Webb of "Dragnet" was born in Santa Monica, Calif.; on June 17, 1953, Sam Fuller's movie "Pickup on South Street" was released, and on June 24, 1938, author Lawrence Block was born in Buffalo.
Then there's the Kahlil Gibran Engagement Diary (Knopf, $8.95), wherein you'll learn that for the week of Oct. 21 to 27, "Generosity is not in giving me that which I need more than you do but it is in giving me that which you need more than I do." Say good night, Gracie.
The Woman's Day Engagement Calendar (Running Press, $10.95) has suitably tough-minded quotes from Jane Goodall, Anais Nin, Ruth Benedict, Joan Baez, etc. The Erma Bombeck Calendar (Andrews & McMeel, $8.95) gives you a witticism a day from the famous columnist. Sample: Feb. 24 -- "My horoscope never minces. It said I was going to have an adventure on water. My contact lens fell in the commode." For Arty Folk Who Want Bang-up Ways to Decorate the Kitchen or the Study: The art selection this year is particularly lavish. From the European company Georgi come some magnificent art calendars with some unfortunately tiny write-in spaces on the dates: One devoted to Impressionists, not just Cezanne and Degas but Berthe Morisot and Max Liebermann, too ($17.95); another devoted to ecstatic English landscape genius J.M.W. Turner ($19.95); another devoted to magnificent fin de siecle symbolist Gustav Klimt ($22.95), and desk-size calendars devoted to Dali and Miro ($8.95 apiece).
Art in Bloom: A Book of Special Days From the Boston Museum of Fine Arts (Universe) may well be the flower painting desk diary of all time. Its only competition would be Georgia O'Keeffe's 100 Flowers Engagement Diary (Knopf/Callaway, $16.95), with paintings, quotes from critics and fellow artists about O'Keeffe and quotes from her own letters.
The Paintings of Frida Kahlo (Chronicle Books, $12.95) presents a Mexican artist who's a cause celebre at the moment for feminists and non-curriculum artists both. On the more practical side, the appointment spaces are nicely spacious.
The Polish Heritage Calendar (Hipposcrene Books, $9.95) presents Polish paintings from the Warsaw Museum.
Those who like their paintings quaint and homespun and commercially folkish should cotton to The American Calendar of Charles Wysocki (Amcal, $10.95) and Kim Jacobs' The Cobblestone Way (Amcal, $19.95), both of which look like cute and idealized children's book illustrations.
The most popular of all calendar perennials -- and the most dignified bit of Americana -- probably remains the Ansel Adams Calendar (Bulfinch/Little, Brown, $14.95) and its engagement-book little brother ($12.95). Adams' mystical reverence for the landscape remains singular, however much copied.
For Fanatics, Armchair Guzzlers and Other Partisans of the Sporting Life: You can't beat Michael Gershman's The Baseball Card Engagement Book (Houghton Mifflin, $10.95) with its avalanche of daily trivia and full-page entries on the likes of losing-pitcher specialist Pedro Ramos, manager Paul Richards and '40s first baseman Rudy York. Hotshots (Little, Brown, $8.95) is a Sports Illustrated sports calendar for kids. The Art of the Trout Fly (Chronicle, $9.95) offers all the glamour pin-ups of trout flies any angler could want.
For Kids: Younger ones will like the 1991 Snoopy All-Star Calendar (St. Martin's/Sparkler, $8.95), and older wiseacre types will have a fine old time with the Bizarro 1991 Calendar (Chronicle, $11.95), in which, for instance, May is commemorated by a family of gorillas saying to an office receptionist, "We want to see the top banana."
For Bread-Bakers, Kitchen Artistes and the Diet Brigade: Jeff Smith's Frugal Gourmet Diary (Quill, $9.95) tells you days of the week and how to make Barbecued Zucchini, Pasta With Clam Sauce and Apple-Fried Pork. The Weight Watchers 1991 Engagement Calendar (New American Library, $9.95) offers Pasta With Tomatoes and Ricotta in July and Pork With Cranberry Apple Relish for November.
For Environmentalists, Earth-Mongers and New Agers: Georgi's The Blue Planet ($17.95) gives you pin-ups of Earth as seen from space, and Simple Things You Can Do to Save the Earth (Andrews & McMeel, $8.95) gives you such daily tips as this from March 15: "Check your car trunk. If you're carrying too much weight, you may be increasing your gas consumption by 1 percent."