SAN DIEGO -- A record number of students are spending Saturday hitting the books instead of the beaches, as summer has become just one more set of classes in the University of California system.

A move to year-round classes and a four-quarter calendar has meant a record number of UC students are taking classes during summer. Campuses like UC San Diego, UCLA and UC Santa Cruz are reporting record summer enrollment.

Faced with burgeoning enrollment and lack of room to expand, the state's highest level of universities are using the summer period as just one more semester, some students complain. "I'm watching summer go by through the window of a library," lamented student Ahayda Ahedi, quoted by the San Jose Mercury News.

One school, UC Santa Barbara, dangles the incentive of a guaranteed and coveted dormitory room for freshmen who skip summer vacation and start their studies immediately after high school. UC Davis encourages students to spend the summer there by waiving fees for all classes over the first eight units.

The entire UC system is using summer school enrollment to move more people through college, enabling more students to graduate on time and make room for others, said Carol Copperud at the UC Office of Planning and Analysis.

Summer school programs used to be fully-funded by students fees, but for two years have been partly-subsidized by state tax funds like all other UC classes. That means summer enrollment has shot up 80 percent statewide over figures seven years ago.

UC Berkeley reports summer enrollment there is up 16 percent over last year.