For John Costa, time is of the essence.

So it is understandable if a grimace washes over his face as he examines the boxes stacked to the ceiling of the tractor trailer that has backed into the loading dock at the United Parcel Service (UPS) distribution center in Vineyard Haven.

It is only a few minutes past 9 a.m. on Wednesday, but the clock tells him it is getting late. He is in a race to move the truck's contents - more than 2,000 boxes of all sizes and assorted packages of varying shapes - out of the trailer by 10:30, when a second truck full of boxes of all sizes and assorted packages of varying shapes will arrive. Both trucks need to be emptied and the boxes sorted and loaded into the smaller delivery vans by 11, when they will be delivered to homes and businesses across the Island.

But what worries him is not that he and his dozen colleagues only have 12 more hours to do it. Instead, he is already thinking about tomorrow, when they will have to do it all over again.

"Ah, it's the most wonderful time of the year," Todd Piggott shouts as he begins to pluck packages from the wall of boxes. "Isn't that right? John?"

Mr. Costa smiles, and jokes with Mr. Piggott and Sean Rooney, who stands across a long, wide conveyer belt that extends to the edge of the trailer. Like the other men in brown who scurry around this narrow building, Mr. Rooney is busy readying his truck for his share of those boxes, which will soon overwhelm the conveyer belt and flood the small room.

"'Tis the season," Mr. Rooney says.

As Vineyarders exchange presents this Christmas, there is a good chance one of these men or their colleagues will have had, quite literally, a hand in getting those gifts under the tree. This week alone, the Island's intrepid brown brigade will deliver more than 15,000 packages to homes across the Vineyard.

Around here, Santa Claus wears a brown suit.

"We did 2,700 pieces yesterday, which is about average for Christmas," says operations manager Vincent Dellatorre. "On a typical day in February, we do about 1,000 pieces, so the holidays are definitely busier. The Internet has really sparked it."

Indeed, the rise of Internet commerce has been a boon to delivery business - and nowhere more than the Vineyard. Mr. Dellatorre said the Island delivery business has grown each year.

"Summers are always the busiest, and it is getting to the point where we have 14 trucks on the road," he says, noting the record for the most packages delivered in one day is 3,382, set last summer.

"I remember when there were four trucks," says Mr. Costa, who has delivered packages on the Island for 19 years. "When I started, we were doing polo shirts from out of L.L. Bean. Now . . ."

He waves his hand over the sea of boxes inching their way down the conveyer belt. It is a who's who of name brand goods: J. Crew, Target, Crate & Barrel, Land's End, Dell, Cabela's and Amazon.com.

"It all used to be Amazon 10 years ago," Mr. Costa adds. "But in the last couple of years Internet orders have really taken off."

From that perspective, Mr. Costa and his colleagues are some of the Island's best armchair economists, with their fingers firmly placed on the pulse of the Vineyard economy.

On this cold morning, an unexpected shipment has arrived, and the sorting begins with a bad feeling: this is going to be a long day. Which is to say, it is going to be a longer day - during the week leading up to Christmas, UPS drivers average 11-hour days, often without a break. All 13 Island UPS delivery men will work well into the night to deliver Christmas packages.

"But it slows down toward the end of the week," Mr. Rooney says. "This year will be the first year I will be able to spend Christmas Eve with my five-year-old daughter."

"Although we are allowed to, we don't even really have time to eat," Mr. Costa says with a laugh. "We are always trying to make our deliveries, and you don't want to set yourself back. I am lucky; I have to take the Chappy Ferry. I can snack then."

For some of the Island's UPS delivery men, the day is actually much longer. Only six of the crew of 13 live on the Vineyard; the others commute from the mainland. One of the younger men, Jeff Torren, adds more than four hours of commuting to his long day. Mr. Torren lives in Westport and drives to Woods Hole every morning for the 8:15 ferry. Usually he gets up a little before six. Around Christmastime, he rolls out of bed at 4:30 a.m.

"It's definitely a long one," he says, placing one of 25 boxes bound for the Colonial Inn in Edgartown inside his van.

Mr. Costa will deliver upwards of 180 packages to homes and businesses across Edgartown and Chappaquiddick. If all goes well, his day will end back at the loading dock around 9 p.m.

The distinction for most miles driven in a day goes to Mark Kokoszka, who drives one of the up-Island routes. He begins his day in West Tisbury and ends in Aquinnah, often traveling more than 100 miles in his journeys down winding dirt roads and through the rolling hills.

"I start at Alley's General Store and end at the lighthouse," he says. "Usually I start with South Road, wind up Middle Road and then work my way back toward Aquinnah. Most of the stops are private homes. I call it my dollhouse route."

Despite the long hours and stress involved in delivering their cargo on time, many of the men stay with the job, becoming familiar and welcome faces throughout the community. Mr. Costa and Mr. Rooney, along with Larry Sylvia, are the veterans. Mr. Sylvia, who has worked for UPS for almost three decades, will retire next year.

"You really develop a rapport with your clients here," Mr. Costa says. "And you especially see that during Christmas."

As 11 a.m. hits, the packages stop rolling off the conveyer belt, and each man begins closing up his van, now packed with boxes. One by one they set off on their routes: Mr. Kokoszka heads to the blinker, where he will split off for up-Island. He is followed by Mr. Torren, who will start at Woodside Village and then move onto the Triangle in Edgartown. Mr. Rooney points toward Oak Bluffs.

Heading for Edgartown, Mr. Costa's truck is crammed with boxes bearing presents for neighbors, friends and family.

"What's funny is when your significant other has something that comes through at Christmastime," Mr. Costa says with a smile. "But my wife learned a long time ago: use FedEx."