Who knew the calendar could cause so much vacation heartburn?

For the first time in five years Independence Day falls on a Wednesday, leaving travelers unsure when to celebrate and worrying those who make a living off tourists.

From 2008 through 2011, the work holiday fell on either Friday or Monday, so employees and their families got an automatic three-day weekend, similar to Memorial Day and Labor Day.

This year, workers will have to burn an extra vacation day or two to get that long weekend.

Despite that fact, Tom Crosby, vice president of communications for AAA Carolinas, said he expects an increase in holiday travel this year.

“Actually, what happens when you have a July Fourth on a Wednesday, you have more people traveling on July Fourth,” he said. “The reason is, you have people who are taking five-day vacations, people who are taking Monday and Tuesday off, and people who are taking Thursday and Friday off.”

He predicts that more people will take off Thursday and Friday rather than the earlier part of the week, so they can watch the fireworks and then relax a couple days.

He also expects the heat wave that started last weekend to cause more people to plan trips later in the week when it might be cooler. He expects travel to be down the first half of the week but up the second half.

For those who are traveling early in the week during the heat wave, he has some advice: Make sure your tires are inflated properly. Emergency roadside service calls for flat tires were up 50 percent Friday and Saturday. Crosby attributes it to the heat taking its toll on tires without enough air in them.

He also advises checking your battery before hitting the road. AAA calls for dead batteries were up 30 percent Friday and Saturday because of the heat, he said.

A handful of local residents who were asked about the midweek holiday Sunday were looking on the bright side.

“It could give employees an extra day of vacation,” said Caroline Edward of Summerville.

Karen Schultz of North Charleston agreed.

“Families might take the whole week off as opposed to a longer weekend,” she said.

The economy weighs heavily on families’ travel plans. Consumer confidence has fallen for four straight months as Americans continue to worry about their jobs and retirement funds. The June reading of a widely followed confidence index was 62. A reading of 90 indicates a healthy economy.

That helps explain why many families don’t seem prepared yet to splurge on vacation. They want to get away but are opting for lower-priced hotels and are looking specifically for properties with free breakfast and Internet. Or they’re choosing instead to stay with friends or relatives.

The typical traveler will spend $749 over six days, down from $807 over five days last year, according to an online survey of 344 people conducted for AAA. Another look at the holiday, by Visa Inc., shows that all Americans — whether traveling or not — will spend an average of $191 on July Fourth activities, down from $216 last year. Visa surveyed 1,012 people by telephone.

“With most Americans continuing to watch every dollar closely, many have realized that sparklers and flag-emblazoned T-shirts are not essential items” Jason Alderman, Visa’s senior director of global financial education said in a statement.

Some don’t plan to celebrate at all. There will be no trips to the beach, no fireworks and no barbecues for 1 in 5 Americans, according to Visa.

The overwhelming majority of Independence Day travelers plan to drive: 35.5 million people or 84 percent of travelers according to AAA. As they do, they’ll get a break at the pump.

The price of gasoline, always on travelers’ minds before a summer road trip, is now an average $3.33 per gallon — down from almost $4 in early April, when there was talk of $5 gas by summer. Whether that will translate into spending more at their destination remains unclear.

“Theoretically, it should boost consumer spending, but so far there’s no evidence of that,” said energy consultant Jim Ritterbusch. “The housing industry is still depressed and that’s keeping people from being confident. They’re going to remain thrifty.”

Another 3.2 million travelers, or 8 percent of holiday vacationers, plan to fly. That will boost their credit card bills: the average domestic round-trip ticket is $391, up 6 percent from last year, according to Travelocity.

Hotel rooms also will cost more. The average price for a room in the top 25 cities will be $140, up 16 percent from last year, according to Orbitz.

Some families haven’t been able to travel for three or four years. There are signs they might finally be ready for a summer trip, whether it’s this week or not.

Adam Weissenberg, who heads the travel and hospitality consulting group at Deloitte, said many families canceled or delayed vacations during the recession.

“People are starting to say, ‘Gee, I need to take a vacation,’ ” Weissenberg said.

Brandy Moore, owner and captain of Biloxi Shrimping Trips in Mississippi, was worried about the mid-week holiday but has ended up selling out her 20-person, 6 a.m. fishing tour for Tuesday, Wednesday, Thursday and Friday. But she attributes it to a better overall summer season, not a particularly strong Independence Day.

“We are just are having a really busy summer all around,” Moore said.

At Kampgrounds of America Inc., which operates 450 campgrounds in the United States under the KOA name, summer bookings are up 5 percent from last year.

But KOA is still feeling the effect of the calendar quirk. Reservations for the July Fourth holiday are down 4 percent.

“It’s the weakest situation we could ask for,” said Mike Gast, the company’s vice president of communications. “We obviously like it to be a Friday or Monday.”

Post and Courier intern Tyler Simpson and The Associated Press contributed to this story.