TAMPAWith bare feet they curled under blankets and propped pillows against a brick wall. Some sat upright with legs crossed on the concrete and jotted in notebooks and buried their faces in thick textbooks. To escape the humid open air, some periodically stepped over to the nearby book drop and opened the hatch to press their faces against a cool blast from inside the locked building.They were a group of about 30 University of South Florida students who camped out from midnight to sunrise Friday at the doors to their school's library. On the concrete, before the immobile sliding glass doors, they did homework all night for a purpose: to protest a recent and unannounced reduction in the library's hours.As the university's fall semester got under way last week, students were surprised to find they would no longer have access to the library 24 hours a day during the week. Budget constraints made university officials adjust the building's hours to close at midnight and reopen at 7:30 a.m. during the week.The students, many of whom work or take classes during the day, were stunned that they could no longer count on the library as a quiet place to study after hours."In general, it is extremely reassuring to know there is always a place you can go on campus to study," said Javin Hatcherian, 29, a USF junior who was among the protesters. "The library is crucial to our academic success."As word spread, students mobilized. More than 1,400 of them signed a petition against the change, which student government leaders plan to present to the university's provost. They assembled a stockpile of facts. Among them: It would cost $136,000 a year to keep the library open 24 hours, according to Hatcherian, which he said equates to about $3 per student per year. And there was the sit-out.McKinzie Step, a USF sophomore who usually studies into the wee hours, was fixated on a technical diagram on Page 47 of a software writing textbook at 11:45 p.m. Thursday, when a library staffer asked her to leave. She walked outside and took a seat next to the others."I have a 4.0 GPA, and I'd like to keep my 4.0," Step said. "It's just really vital to my success here."Several students said they can't study anywhere else. Starbucks is too noisy. So are many of their dorms and off-campus apartments, where fellow students tend to stay up all hours partying."Some of us got jobs (before school started) with the understanding that the library was going to be open," senior Kyrie-Leigh Chambliss said. "Sometimes you have to pull an all-nighter."Bill Garrison, dean of USF libraries, said that an article published Monday in the Oracle, USF's student newspaper, made clear to readers that library employees "fought tooth and nail" against the change in hours, proposed as a budget item last spring."We did not want this action taken," Garrison said. "The students knowing that really took pressure off the staff."A recent student government survey asked students from the school's St. Petersburg campus about the change and found that most disapprove of the cut in hours, said Christa Hegedus, vice president of the USF St. Petersburg Student Government."It is a surprise," Hegedus said. "We just had this influx of new students, and the hours have been lowered. People don't really understand."Times staff writer Alison Barnwell contributed to this report.