For many, the 24/7 economy has become an indispensible part of life - calling a help desk after midnight to fix a computer glitch or dropping by the local minimart before daybreak on a fishing excursion are conveniences we simply take for granted.
Far fewer of us, however, actually work those wee hours of darkness.
Employees who work shifts between 9 p.m. and 8 a.m. accounted for just 3.5 percent of the full-time workforce in 1997, according to the most recent survey data available from the US Bureau of Labor Statistics.
But their ranks are growing, note experts in night-shift issues.
Global competition, instant communications, and changing consumer habits have prompted many US companies to start operating around-the-clock, says Dean Croke, a consultant at Circadian Technologies, a Lexington, Mass., firm that advises employers on safety and efficiency issues associated with 24-hour operations.
"Businesses have looked at economic models and say, 'We only run our plant 12 hours a day, why not run it 24 hours a day?' " says Mr. Croke, noting that there is great pressure on companies to utilize assets that otherwise sit idle.
A study by Circadian last year found that 23 million people in the US work outside the traditional 9 a.m.-to-5 p.m. block, including those on the night shift. That's up from 19 million a decade earlier, Croke notes.
Still, night-shift work remains concentrated in public-service-oriented jobs: police officers, firefighters, hospital workers. Night-shift work also is common in some goods-producing industries - like mining and chemical manufacturing - where it is more efficient to operate continuously than to shut down at the end of the day and start up again the next morning.
The Bureau of Labor Statistic's 1997 survey found that men were somewhat more likely than women to work nights.
Those who had never been married found themselves on the night shift more often than their married counterparts.
While some people enjoy the flexibility of working nights, there are "a lot of problems" that result from flipping the body's normal rhythms, Croke notes, including sleep deficits that can add up to an entire night's shut-eye in one week.
"The physical strain is incredible," he says, pointing to various ailments that some have linked to sleep deprivation, not the least of them being impaired judgement.
Circadian Technologies will tell a company it's OK to use the 24/7 model, Croke says, "but they must have countermeasures to ensure people don't fall apart at the seams."
Such measures include illuminating the workplace with bright lights, setting the temperature at a cool 68-70 degrees F., and introducing a napping strategy that may feature a darkened nap room, where employees can recharge without distractions.
A look at how some workers make it through the night:
It's early in the morning at RealNetworks' Real Broadcast Network in Seattle, and there's just one man running the show.
At the helm of RBN's impressive, glass-window-enclosed Broadcast Operations Center (BOC) sits Deva Maheswaran, a Sri Lankan native with a disarming, gentle sense of humor.
Deep inside RealNetworks' downtown Seattle headquarters, Mr. Maheswaran spends his work nights watching over a panoply of live video and audio feed - streaming media, as it's called - delivering news, information, and entertainment to Web surfers everywhere.
Under the glare of the monitors lining the wall, Maheswaran works the 9 p.m. to 7 a.m. shift four nights a week, watching over Net feeds ranging from CBS's "Big Brother" to live scientific programming from NASA TV.
The kind of network maintenance necessary for RBN's operations to run smoothly is easier to do late at night, says Maheswaran, when Internet traffic is slower and when there are fewer people around to distract him from the task at hand.
From the BOC, Maheswaran is able to steer RBN's 12 satellite dishes and to make sure that all scheduled events are broadcast online as planned.
Maheswaran came to the US in 1981, after completing high school in Madras, India, where his Tamil family had relocated in light of increasing civil strife in their homeland. While earning a dual degree in electrical and computer engineering, Maheswaran got his first taste of the overnight-worker lifestyle, working as a janitor in order to pay for his education.
In the two decades that followed, Maheswaran earned his citizenship, and estimates that he has worked at least a hundred temporary jobs, many at odd hours of the night.
The more steady job at RealNetworks, which Maheswaran got three years ago, was the product of his mother's insistence that he finally put his academic degrees to use.
Despite offers to move into regular daytime work at the company, Maheswaran, who is also the drummer in a Seattle punk band called Ward A, has stayed put. He says he's still willing to put up with the inevitable exhaustion that accompanies a "graveyard" shift.
"I must be crazy or something, but I like it. I feel like I get more done, and there are no interruptions. I keep looking at the advantages of the job."
- Silja J.A. Talvi
Chris Carter loves his job as a radio disc jockey, but sometimes he wonders if anyone is listening.
As an on-air personality at Star94 in Atlanta, Mr. Carter plays mainstream top-40 hits from midnight until 5:30 a.m. five times a week.
He works on the top floor of a 20-story building. And except for the security guard in the lobby, everybody is long gone by the time Carter's workday begins. The DJ says loneliness sometimes hits between 3 a.m. and 4 a.m., before most people start getting up for work.
"Because there isn't the traffic on the phone like there would be during the day, I have to fill the space with something entertaining," he says. "I try doing a lot of show prep, such as [compiling] artist information. People are interested in details about famous people."
Carter joins the ranks of a shrinking number of DJs who work overnight. Having worked as a Star94 night owl for the past year and a half, Carter says he and his fiancée are used to the schedule.
"We have dinner together every night, and I see her every morning," he says. "She sleeps during the night while I'm at work, and I sleep during the day while she's at work."
To help him sleep, the radio personality's bedroom has dark heavy curtains. "I do get woken up almost every day when the mail gets delivered between 12 and 12:30, because my dogs don't like the mailman and there's nothing I can do to shut them up," he says.
So what draws him to the airwaves during the wee morning hours?
"I love the idea that I can walk into a room in the middle of the night and push a button and speak to a lot of people. It's kind of a surreal feeling," Carter says. "It always amazes me what people will tell me, because they don't know me, they can't see me, and I'll never meet them."
The nighttime blanket of darkness has made Carter take some things for granted. Over a period of several months, he commuted by a housing development under construction. In the darkness, he never noticed it.
But driving once during the day, he was surprised to see a completed development that seemingly had sprung up out of nowhere.
"I get a lot of that from other people who work the graveyard shift," Carter says. "Things look so much different in the dark than [in] the light. When you see things from a different perspective, it's strange."
- Leah G. Rothschild
At 5 a.m., on a recent summer day, the Los Angeles freeways are already filling with commuter traffic. The sun is still a suggestion in the eastern sky, while a near-full moon is only just beginning to fade.
And Jose Dircio is facing the hardest part of his day - the last hour of his shift as a waiter at one of L.A.'s dining institutions.
"It's always the longest hour," says the immigrant from Mexico City. "You're just waiting for the next waiter to come. You think he's never, never going to show up."
Mr. Dircio has been working this shift three nights a week for the past 18 months at the Pacific Dining Car - a popular downtown steakhouse that has been serving chow 24 hours a day for 80 years.
He took the job for one reason: so he could attend school during the day to earn his high school diploma.
"You have to have a goal in order to stay on this shift," he says. "You say, 'OK, I'm doing this because it's for my future. There is no other way to go to school.' "
One of six children, Dircio tries to send money to his parents and siblings back in Mexico City every few months. (He also works two evening shifts a week as a busboy at the restaurant.) He attends school in the afternoon and early evening.
His work schedule - and his homework - shot down his last attempts at having a girlfriend. Occasionally, he catches up with friends by telephone or shooting hoops for an hour or two at a local court.
He misses the sun, but admits that there's something wonderful about the calm of city streets late at night, when few cars are on the road.
Things will change, he says, when he gets his high school degree in December. He'd like to be a computer programmer, but knows he needs more education. Then, diploma in hand, he'll try to find a day job.
"It's really hard," he says of the late-night work. "But it's worth it, I think."
- Sara Terry
It's 2 a.m. on a recent Monday, and veteran toll collector Mark Smyth is full of energy. As drivers approach his booth at 20-second intervals, he takes their extended bills, drops change into waiting hands, and deftly tosses the 50 cent fare over his shoulder into an automated toll basket.
The Manassas, Va., resident also tosses out something extra: one of the sunniest two-second greetings that late-night drivers on the Dulles Toll Road near Washington could ever expect to encounter.
"Thank you ma'am for using the toll road," Mr. Smyth smiles to a woman in an SUV. "You're welcome, buddy," he responds to a man appreciative of some directions. "You have a real good evening, now," he chimes to just about everyone else.
"I enjoy being a toll collector," says the 12-year veteran of the Virginia Department of Transportation. Smyth has spent the past 6-1/2 years working the night shift from 9:15 p.m. to 5:45 a.m.
"I enjoy meeting the people," he says simply. "Although it gets slower around 4 o'clock, I just look forward to each and every person who comes through."
No matter how late it gets, drivers almost always return his friendly sentiments.
"You make eye contact," he says. "You can pass on a lot of information in a few seconds."
Smyth left a less-than-friendly job as a retail analyst for the Sprint telephone company before joining the toll-collecting force.
"When I got into the corporate world, I wasn't much for the cat-fighting that goes on as you climb up the ladder," says Smyth, who has a degree in business from Kansas State University.
His original plan for the job was to take some "mental rest" and then to move on. But Smyth discovered that he liked his co-workers, liked the public, and particularly liked the night shift lifestyle.
Smyth lets his body govern his sleep schedule, sometimes going to bed in the morning and other times in the afternoon. His windows are blackened to fool his internal body clock.
He admits that it's not a lifestyle suited for everybody - married couples with children, in particular. But the advantages to him are clear.
"It frees you up to do a lot of things during the day," he says, ticking of a list of hobbies that include hiking and exploring nearby Civil War battlefields.
"We were once kids. By the time we got good at being kids, we were adults ... and we were working. You could never go out and play anymore. My days are free. I can do what I want."
- Neal Learner
Two hundred and eighty-five feet above Boston, the city is nothing but lights.
The bright downtown skyline rises off to the west; below, a confusion of blue, red, and white lights signal the runways at Logan International Airport.
Inside the airport's dark control tower, flickering green screens show plane positions, weather maps, and flight plans.
It's here that Bob Francis and the other air-traffic controllers keep up a running stream of cryptic aeronautic jargon, talking through their headsets to pilots, giving instructions to each other.
Every instant they're barraged with visual and sound cues. "It's a knack," Mr. Francis says, thinking about what makes a good controller. "It's the ability to process a lot of information at the same time. I can be talking to my wife and one of my kids at the same time. It flabbergasts my wife."
When Francis was a kid, he would "look up at that tower and say, 'I want to be there,' " he remembers. He joined the Air Force with that goal in mind, but after a medical discharge, he'd all but given up on his childhood wish.
Then, working as a limousine driver, he picked up an air-traffic controller one night. Offhandedly, he told his passenger about his old dream.
"He gave me an address, and I wrote to it," he says. An aptitude test, a medical exam, and months of training later, Francis was finally standing in a control tower himself.
A quiet, bearded man with a slight Boston accent, Francis lights up when he talks about his job, which he loves. "It's the adrenaline," he says. "The best times are when it's busy and you can move a lot of airplanes. And the view? It's beautiful, night-in and night-out."
This particular night is perfect summer weather, and Francis and the other controllers are moving more than 100 planes per hour. On bad-weather nights, Francis says, it's more hectic, and also more frustrating. "Last night, we had 7,000 minutes of delays.... You put yourself in the passengers' shoes."
He admits, though, that one of the pleasures of working in the tower is watching thunderstorms roll in, and he remembers one eerie day when the clouds were settled so low and thick that the tower was above them. He could hear the engines roar when planes took off, but he wouldn't see them till they popped up through the fog.
Most people have an inflated idea of his job's stress level, Francis insists, inspired more by Hollywood than reality. Day to day, he says, the planes are just numbers.
"But when something goes wrong, that's when you realize the gravity of it." Recently, he witnessed a plane crash. He wasn't involved, but he could see it through his binoculars.
"Until I heard they were OK, it was probably one of the worst times in my career," he says. "It's not [stressful] until those times."
As the night progresses in the tower, it gets quieter. Due to tight noise controls, few planes come in to Logan in the early hours. Many of the controllers, who vary the eight-hour shifts they work, will go home.
For Francis, the constantly rotating schedule means he can't always make his kids' soccer games and dance recitals, or even be home on Christmas morning, but he doesn't mind.
His four children, naturally, love what their father does. "They're bugging me to come up to the tower," he says.
- Amanda Paulson
Approaching 9 p.m. in Sioux Falls, S.D., the sky is copper and strangely serene. A tornado has just passed through, touching down in Lennox, a sleepy nearby town of about 2,500.
Trooper Lori Olney receives her assignment over a crackling radio. A diminutive but stern woman with bookish glasses and a quick smile, Ms. Olney presses the gas pedal. The engine of her patrol car lifts and whines, kicking the speedometer to 90 m.p.h.
"Tonight we'd planned to work a checkpoint for drunk drivers," she says, "but the governor is in the area because of the tornado, and my boss wants us there."
Fifteen years ago, the single former schoolteacher traded her eraser for a badge of the South Dakota Highway Patrol. Since then, depending on her rotation, she keeps a lone, lynx-eyed watch for lawbreakers traveling the nighttime Interstate. "The night shift runs to five," she says. "I usually get coffee around four."
She has no children, but each shift begins and ends with a long, contemplative walk with her dog. "We even went out before tonight's shift, in the pouring rain," she says.
Drunk drivers take up much of her time. But anything can happen. In Lennox, the tornado has felled trees, damaged a few buildings and knocked out the town's power. Olney's assignment: Enforce a town curfew.
Around midnight a truck flags her down. The driver explains that a sling used to lift a disabled person into bed had broken. Some townspeople are in the hardware store trying to fix it. But they need a flashlight.
Within minutes, Olney is standing in a pitch-black room, her flashlight beam on four men huddled over a vice, straining to bend a steel bolt. "That should do it," one says after several minutes. "Thanks, officer." Back in her car, she buckles up and tells the dispatcher she's back in service.
"I don't know if I'd do this job anywhere else," she says. "People here are good. They're respectful of us."
Five more hours to go.
- Kelly Hearn