For many students, Thanksgiving break is a chance to duck away for a long and nutritious weekend. The earlier it starts, the better -- even if (or especially because) there's class to be missed.

That's been the attitude of students -- and many professors -- ever since turkeys and cranberry sauce came to symbolize bonding, unity and awkward family reunions. Mindful of the inevitable declines in attendance on the last day of classes before break, some colleges have traditionally left it up to professors to decide whether to cancel lectures or to include optional material. Others have taken the opposite tack, juggling the academic calendar or dangling incentives to keep students on campus until classes officially end.

"Giving tests and quizzes works. And the students love you for it, too," quipped Hank Gorman, an associate professor of psychology at Austin College, north of Dallas, Texas.

Austin, which holds classes through noon today, will face the same challenges as other colleges during the rush home for the holiday. Some professors may make allowances for an absence on the day before Thanksgiving, and at least one Austin professor tries to lure students with cookies. (It's not clear, however, whether those will win out over homemade pumpkin pie.)

As a result, students are sometimes left with mixed messages; some professors cancel classes while others mandate them. The University of Virginia's student newspaper, The Cavalier Daily, reported this week that some students whose last classes fell on Tuesday were complaining about the break schedule, which last year began on the Friday before Thanksgiving, but this year doesn't begin until today.

"It's a little irritating because I have three classes and only one that I actually have to go to," one student told the newspaper. "My other classes have been canceled, so otherwise I'd be out of here."

Jeffery G. Hanna, senior director of public affairs at the university, said the academic calendar tended to vary from year to year depending on the number of instructional days needed and other factors. Late Tuesday afternoon, he saw four chartered busloads of students ready to leave campus. "There were a lot of students still around," he said.

Even if U.Va. hasn't necessarily altered its course schedule for the purpose of keeping students on campus, other institutions have found that a little calendar tweaking can ease the burden on both students and faculty. At Salem State College, a commuter school nestled in old Pilgrim country, "classes were held on the day before Thanksgiving, but the attendance was so low that we adjusted our calendar accordingly," wrote Karen Murray Cady, the director of college relations, in an e-mail. Officially, today is a "reading" day, she added.

Plymouth State University (in New Hampshire, not Massachusetts) takes a similar approach, but its director of public relations, Christopher M. Williams, warns that it isn't the length of the break that's the most important factor in determining class attendance. Some students will always want to start a day early. "We could have the whole week off and we’d just have the problem on Friday as opposed to Monday or Tuesday," he said.

More creative solutions also abound. Phylis Dryden, a professor emerita of English at Lebanon Valley College, in Pennsylvania, used to give what she called "Just-for-Fun" quizzes on the day before Thanksgiving. (Sample question: "What color is an orange? Black, white or orange?") "It was great fun and helped raise the quiz grade for all students, while having a minimal effect on the quiz average for those who opted not to be there," she said in an e-mail.

At the College of Wooster, in Ohio, two organic chemistry professors devised a lesson plan that was relevant to both the subject material and the time of year: They held a class on the chemistry of Thanksgiving. "We’ve never really had attendance troubles," said Paul Bonvallet, one of the professors. Then again, that's not necessarily a surprise for a course that has a one-question quiz at the beginning of every class -- including on the Monday before Thanksgiving.

"What do I think the solution is on a larger scale?" wrote Michal Ann Strahilevitz, a marketing professor at Golden Gate University. "Each university needs to have a clear policy on whether Wednesday afternoon and evening classes should be canceled the day before Thanksgiving. If everyone sticks to a policy, students won't boo or cheer at individual faculty members for holding or canceling class. They will just learn to live with it, just like all the people that go to work every year on the Wednesday before Thanksgiving."