Harvard students pulling all-nighters and workers on the late shift no longer have a haven in Cambridge -- for the first time in memory, the Hayes Bickford is closing early each morning.

Assorted incidents of vandalism -- plus the desire to get rid of all-night loiterers and have time to clean the place up--have forced the Bick to close for an hour at 4 a.m. every morning.

The new policy began last Sunday morning, when a sign reading "Closed 4 a.m. to 5 a.m." greeted bewildered would be customers.

An eyewitness reported that there were about 25 people in the Bick when the night manager told everyone to leave, explaining that employees needed time to sweep the floor and clean the grill.

Some 15 customers didn't budge until a squad car pulled up at 4:15 and two policemen ordered them to leave. Another policemen stood outside the cafeteria until it re-opened at about 4:55. Then, grumbling under his breath about the policy, he marched down to the Waldorf for breakfast.

Paul Bickford, general manager of the Hayes Bickford system, added that most stores in the system already close at 4 or soon will.

Closing for an hour each morning cleans the customers out and prevents them from "nodding over a cup of coffee all night," he said.