During a recent visit to the University of North Carolina at Chapel Hill, Associate Registrar Daria Vander Veer ’87 decided to take an early morning run, around 7:30 or 7:45, and what she saw surprised her: students heading to class.

At a school like UNC, with a total undergraduate population of nearly 30,000, students told her, they had simply become accustomed to the necessity of having class at such an early hour.

“For sheer survival, they just have to use the entire day,” she said. “It had just become part of the culture.”

But even on Yale’s busiest days — Tuesdays and Wednesdays — only two percent of students head to class before 9 a.m., according to John Goldin, director of the Office of Institutional Research. By contrast, 73 percent of Yalies are signed up for class at 10:30 and 11 a.m. Wednesdays, the time slot with the most course traffic.

Indeed, the bulk of Yale’s classes are held in the late morning and early afternoon, according to Goldin’s data from fall 2009, and only a handful meet Fridays. For students, the midweek, midday bunching of classes forces trade-offs that would not be necessary were classes more spread out; for departments, the clustering is an administrative headache as the best classrooms get snatched up and overlapping class times limitenrollment.

Though faculty hold most of the control over when they teach, student demand also plays a role, registrars and department administratorssaid; most professors seem willing to hold class in the morning, but late-night extracurriculars make classes before 9 or 10 a.m. less appealing to students.

The scheduling process is roughly the same in each department: Faculty members tell the director of undergraduate studies when they want to teach, and the DUS works to develop a schedule that satisfies as many faculty members as possible. In larger departments, more players are involved — last year, members of the English department’s six-person Undergraduate Studies Committee made a wall-to-wall chart of all its classes in hopes of convincing professors to move their classes from the busiest time slots, DUS Amy Hungerford said.

To reduce the strain on classrooms, the Registrar’s Office has suggested that departments spread out their classes as much as possible. But competing interests, from research to family restraints,have hindered departmental efforts to follow through.

Often, the decisions of large departments such as English and History end up determining the schedule of the entire University. In the African Studies Department, for instance, DUS Ann Biersteker is responsible for scheduling only language classes and two required classes she teaches — the rest are primarily listedwith departments like History, Political Science and Anthropology,which determine the schedule. She said she would only suggest a time change if she expected two conflicting classes to be popular; otherwise, the decisions are all made for her.

“We’re so small, we’re just happy if someone offers a course on Africa,” Biersteker said.

And while scheduling a class during a busy time slot can take a toll on enrollment as students are forced to make tough decisions, holding a class in the morning hours or on Fridays,when some students leave campus, can cause its numbers to drop. Creating a more even spread of classes, Vander Veer said, would take a major cultural change.

Though Vander Veer said she can always find a classroom for a professor, even in the busiest time slots, that classroom might not be ideal.

For students, the bunching can be frustrating. All four of McKenna Keyes’ ’14 top choices — Introduction to Ancient Greek History, Introduction to Psychology, a freshman seminar and a writing seminar — are offered from 1-2:15 p.m. Tuesdays and Thursdays, forcing her to seek other options.

But tight scheduling isn’t unique to Yale. At Stanford University, 69 percent of courses begin between 10 a.m. and 2:15 p.m., and while the spread of classes is fairly even Mondays through Thursdays, classesFridays are uncommon, Senior Associate University Registrar Sharon Velten said.

Goldin, for his part, said he hopes more work is getting done on Fridays than his data indicates, though he said he, too, takes the day off.