When night school means college courses at 2 a.m.

What are you doing tomorrow morning before breakfast -- or after midnight? If the answer is "sleeping," you're out of step with a growing number of busy , very eager learners who are snatching a little more education during odd hours of the day and night.

As colleges and universities realize that the coming enrollment crunch is likely to bring them fewer full-time, live-in students in the 18-to-21 year-old age bracket, they are reaching out to an often older and busier group of students with more-flexible class schedules and part-time programs.

Last year, officials of Triton College and Technical Institute, a public community college in a western suburb of Chicago, noticed that their daytime computer operator courses were overflowing. They decided to launch an experimental series of technical courses running from 11:30 p.m. to 3:30 a.m. to meet the schedule needs of second-shift factory workers. The result was so successful that Triton has more recently begun a 7 a.m. "breakfast college" of 50-minute courses in every field from yoga and algebra to philosophy and investing. Its pitch, with apologies to American Express, is: "Education -- don't leave for work without it."

Sandwiching education into odd hours has advantages, but it usually calls for adjustments. Jim Jenkins, who signed up for Triton's nighttime machine tool course earlier this year, reports that the choice of parking places near the class at that hour was superb -- "no more of that driving around, waiting for someone to leave a space." But he says he had his regrets about leaving his wife with the chore of getting up every few hours to tend their infant son.

The hardest part, says Mr. Jenkins, was getting up after only three hours of post- class sleep to get to his 7 a.m. first-shift job. But between having an "excellent teacher who kept us awake" and cat naps at other hours of the day, he says he now is eager to sign up for an advanced machine tool course on the same "night owl" schedule.

While some urban institutions and community colleges long have tried to tailor their offerings to the needs of students with demanding jobs and family responsibilities, conventional colleges and universities now find that they must adapt as well if they want to survive and grow.

"More and more traditional colleges are moving out of the 9-to-5 mold to offer late afternoon, evening, and weekend courses aimed at the part-time student," says Kenneth D. Young, executive director of the National University Continuing Education Association.

While some of the courses are technical, aimed at the updating job skills, and some are strictly for enrichment, an increasing number of part-time programs lead to degrees. According to Karen Hegener, editor in chief of the Peterson's education guide series, some 957 two-year colleges and more than 1,200 four-year institutions, including Harvard University, now offer part-time degree programs.

One increasingly popular route to both undergraduate and graduate degrees is an intensive schedule of weekend classes beginning Friday evening and lasting through Sunday afternoon. Some, like Mundaline College in Chicago, even maintain a separate "weekend" faculty and offer residence facilities. Usually students attend every secon or third weekend. Many are women who never finished studies for a bachelor's degree and who shoulder the same mix of family and job responsibilities.

"I think in night classes you can feel king of lost and alone and tired," says Carol Straub who has been studying at Milwaukee's Alverno College every other weekend. "But I can't say enough that's good about this weekend program. There's a feeling of sharing and mutual support because we're all constantly juggling the same priorities."

But the search for the right time and subject mix continues strong. Whatever new variations may still lie ahead as more students grab education on the run, the traditional picture of the four-year, live-in college student is changing fast.

"Two or three decades ago colleges had more students than they could handle but now, for the first time, the part-time student really has an equal shot at a college education," says J. W. Peltason, president of the American Council on Ed ucation.