The much-touted extension of universal keycard access (UKA) to 2:30 a.m. for upperclass students officially debuted early yesterday morning to a quiet but welcome reception by Harvard night owls.

For the most part, silence reigned over the entryways of the river Houses after 1 a.m.

But some nocturnal students were already taking advantage of the later keycard hours to visit friends in other Houses.

Neil D. Shah ’03, an Eliot resident, swiped into Kirkland House at 1:45 a.m. in order to visit a friend.

Shah said he was aware that the extension would go into effect at the start of the semester and was grateful for the increased access to other Houses.

“It’s good because it lessens a lot of hassles,” Shah said. “Even more so on weekends because the parties usually go on until after 1 a.m. and there’s stuff afterwards.”

Shah said he did not share some Masters’ fears—expressed when they approved the change earlier this month—that later UKA would increase the risk to House residents’ safety.

On the contrary, College students on the streets of Cambridge early yesterday morning said they thought later UKA would decrease students’ vulnerability.

“It feels safer knowing you can swipe into any House,” said Ceridwen Dovey ’03, a Currier resident, as she stood in front of Lowell House at 1:40 a.m.

Kate P. McDavitt ’04 also said that she felt much safer knowing she could stop at any House as she walked down Plympton Street to the DeWolfe Street apartment complex a bit after 1 a.m. yesterday morning.

Zachary M. Gingo, manager of administrative operations for Faculty of Arts and Sciences physical resources, said Harvard Yard Operations technically changed the time code for House doors on Monday. Thus students could actually swipe in the day before the extended hours officially went into effect.

Gingo said Yard Operations had its student employees check that UKA was in effect after 1 a.m. Tuesday morning.

The Masters voted Jan. 16 to extend keycard access on a trial basis for the spring semester, despite the lingering fear of some Masters that the measure would decrease safety in the Houses.

Dean of the College Harry R. Lewis ’68, who supports later UKA, warned at that time that the 2:30 time will not become permanent unless students demonstrate this spring that the change does not cause increased safety and noise problems.

The decision came after years of lobbying by students for 24-hour UKA, spearheaded by the Undergraduate Council.

—Staff writer Anne K. Kofol can be reached at kofol@fas.harvard.edu.