On deadline day at Liberty Tax Service on Harford Road, a young woman in a green Statue of Liberty costume stood out front waving frantically at passing cars.

But on Tuesday morning, you'd never know a deadline was looming from the relative calm inside the Parkville storefront office. Two tax preparers sat across desks from customers, methodically entering information into forms on their computers.

Manager Neil Riordan figured most people had no idea they had two extra days to file their tax returns, since the 15th fell on a Sunday and Monday was a local holiday in Washington, D.C. Riordan said the office saw a rush of down-to-the-wire filers last week. Usually April 15 is the last day taxes can be filed.

"It was unusually busy," he said of last week. "People thought they were beating the deadline."

But just as surely as tax returns come due every April, there will always be customers slipping in just before the deadline, Riordan said. That included a half-dozen people dropping in Monday night.

Typically, "those are people that owe," he said. "They are not in any hurry to file taxes."

Sam Wernick, a 24-year-old Parkville resident, said he had no good excuse for waiting until Tuesday to gather his paperwork and stop in at Liberty, where his brother had his tax returns prepared. Wernick blamed procrastination and his busy schedule as a software tester.

Would he get a refund?

"Probably not, unfortunately," Wernick said.

Wernick was joined by another customer, who was filing two years' worth of returns. Office staff planned to keep working until 9 p.m. and expected more last-minute filers Tuesday evening.

Local tax filers who need to mail a check postmarked Tuesday had less time to do so than in previous years. Many post offices closed at 5 p.m., their regular time. The main Baltimore post office, on East Fayette Street, was to close at 7 p.m., according to the postal service's website. In previous years, the main post office was open until midnight on tax day.

Even though electronic income tax filing likely has prompted more people to prepare their own returns, business has been brisk — and grown each year — at the eight Liberty Tax offices owned by Robert Mufareh and his three partners, Mufareh said. They opened their first franchise eight years ago and now own seven offices in Baltimore City and Baltimore County, he said.

Some customers come to Liberty to have their self-prepared returns double-checked. The preparers do that for free, but they often find errors that must be corrected — such as missing paperwork or credits that were overlooked — which means more business, Mufareh said.

But many people don't even attempt to do their own taxes, he said.

"A lot of people don't want to mess with it," he said. "They want someone else to do it to make sure it's done right. Everyone is scared of the IRS."

Shelley Keirn, a certified public accountant with Stoy, Malone & Co. in Towson, said Tuesday that she and her colleagues have been working long hours and weekends for the last three weeks. On Tuesday the staff was busy filing last-minute extensions for taxpayers — who still had to remit payment Tuesday if they owed money.

She estimated the firm would handle about 100 returns Tuesday.

"We're making sure we have everything that we need," Keirn said, emphasizing that it was up to clients to write — and mail — checks if they owed money to the government. "The ball's more or less in their court."

Still, she expected a late night.

"One of the jokes here at the office," Keirn said, "is it always gets done and we don't leave until we ensure that it gets done."