BOSTON (Reuters) — In this windowless classroom, with cinder-block walls and fluorescent lighting, it could be any time of day, but the wide yawns, drooping eyelids and giant urn of free coffee suggest this is no ordinary college class.

Welcome to Bunker Hill Community College instructor Charles Daniel's writing class, one of five this semester scheduled from 11.45 p.m. to 2.30 a.m. due to surging enrolment.

"The idea of midnight classes was something of a novelty, but it's turned into a necessity," said BHCC President Mary Fifield. "Students are looking for a way to start their college career, and all the day, weekend and early evening classes were closed."

Bunker Hill, in Boston's Charlestown neighbourhood, is about three miles from Harvard University.

But the hardscrabble school, which sits in the shadow of an interstate highway, seems a million miles away from prestigious Harvard, frequently ranked the best university in the world.

Competition to get into schools like Harvard is always intense. But on the other end of the spectrum, community college enrolment across America is surging as students on a budget look for a way to get a higher education.

Nationally, enrolment in community colleges surged by 16.9 percent to 8 million in fall 2009 from two years earlier, according to the American Association of Community Colleges.

The deep U.S. economic downturn has forced many families to look for less expensive ways to send their kids to college, and encouraged older workers to pick up new skills.

U.S. community colleges, primarily two-year public institutions, are seen as a viable alternative for getting started on a four-year college degree.

A year of full-time tuition at BHCC is about $3,000, much less than public four-year universities. Many students also hold down jobs to help pay their modest tuition bills.

U.S. public four-year colleges charge, on average, $7,020 per year in tuition and fees for instate students, with students from out of state paying an additional $11,528, according to College Board data.

In Massachusetts, instate tuition is $9,240 at four-year public colleges — three times BHCC's cost. Tuition at Massachusetts' private four-year colleges averages $33,762.

High unemployment has also pushed older adults to boost their skills or retrain for another profession.

Many students at Bunker Hill hold down one or more jobs and look for classes that fit their sometimes irregular schedules.

Among the BHCC night students is 29-year-old Eric Reddin, taking his first college class. Reddin, who served in the US military in Iraq and Afghanistan, lives in a Boston shelter for homeless veterans. Military benefits will pay for his tuition, books and, ultimately, a housing allowance.

Like Reddin, thousands of veterans are enrolling in community colleges, especially in areas with large military populations such as San Diego and northern Florida.

Bunker Hill is the largest community college in Massachusetts. Fall enrolment is about 12,200 students, up 12 percent on the year and 27 percent higher than two years ago.

"We see the pattern over and over when there is an economic downturn, and this downturn has been particularly severe," said Norma Kent, AACC spokeswoman in Washington.

Bunker Hill's experiment with "midnight oil" classes began with two classes a year ago.

Now classes from algebra to sociology, are on the late timetable. "If it sounds reasonable, we'll try it," said Fifield.

A handful of other colleges, from Maryland to Illinois to California, have followed Bunker Hill's lead and are offering midnight classes to cope with overflowing enrolment.

Leading the writing class, Daniel is personable; a slightly chunky, baby-faced man in rumpled khakis and striped shirt.

"I want you to get to a point of some elegance, some conciseness," he tells the 12 male and seven female students. "I want you to shape your writing a little more tersely."

The attendees range from recent high school graduates to the unemployed, to workers looking to launch new careers.

Some came to class straight from their jobs at area hospitals, post offices, restaurants and retailers. Others ended in the midnight class after all others filled up.

"I think it's awesome. I wish they had a whole program like this," said Peter Bonna, 48, a veteran cop coming off a 16-hour workday in Boston's tough Roxbury neighbourhood. Bonna will soon retire and intends to retrain as a nurse.

Next door to Daniel's class, instructor Kathleen O'Neill teaches a midnight "Principles of Psychology" class.

She brings home-made cookies and says she tries to make the class lively, "like Sesame Street," to invigorate her weary students.

The dedication that many students show in handling sleep deprivation as well as juggling jobs and families helps motivate the instructors, O'Neill said.

Daniel keeps conversation going and the handouts flowing as the clock grinds past 2 a.m., although even his eyelids sag during a debate on the elements of a strong thesis statement.

"Students often dislike 8 a.m. classes," might be a good point of argument, Daniel suggests.

To which Reddin replies to loud laughter from his classmates, "Midnight classes are worse."