In a surprise move, Oak Bluffs selectmen on Tuesday unanimously agreed to extend last call and closing time at town bars and nightclubs by one half hour on a trial basis, meaning patrons can now get a drink up until 1 a.m. and stay in an establishment until 1:30 a.m.

The proposal was presented by police chief Erik Blake, who said the intent is to reduce the crowds that routinely gather along Circuit avenue after last call. An important provision, he explained, is that police will enforce a strict no-admittance policy to bars after 12:30 a.m., the same time as last call for bars in Edgartown, the only other Island town that serves alcohol.

Once someone leaves a bar after 12:30 a.m., they will not be permitted to return. The chief said he believed people who gather outside the bars will be less inclined to wait around an extra half hour. “What is happening now is several hundred people wait around to see the show . . . they wait around to get phone numbers and find out where the party is. Hopefully this will reduce the party-like atmosphere,” the chief said.

Selectmen initially considered extending the hours of operation through June only, but agreed to extend the trial period through the Fourth of July weekend. At their July 8 meeting they will decide whether to permanently adopt the new hours of operation.

Discussion was brief and the motion to approve the trial period for the longer hours was approved with little fanfare. Selectman Kerry Scott, who last year pushed to muffle noise and loud music from downtown bars, briefly asked whether the town should inform abutters and neighbors before voting.

She also asked town administrator Michael Dutton to send a letter to Edgartown police chief Paul Condlin informing him of the decision.

Stuart Robinson, co-owner of Smoke’N More Bones on Circuit avenue across from the Lampost, asked selectmen if they would agree to extend the hours for take-out restaurants that do not serve alcohol. But Mr. Dutton said hours of operation for restaurants are a town bylaw, and any change would need approval by voters at town meeting.

Several bar owners attended and said they support the change.

Following the meeting, Helen Scarborough, a resident of Central avenue and one of many Camp Ground residents who has voiced concern about noise and loud music from downtown bars, said the news came as a surprise.

“That’s the first I’ve heard of it. I don’t think anyone in the Camp Ground was aware it was being considered,” she said.

Mrs. Scarborough said selectmen and police have been diligent about keeping noise levels down and protecting the peace of the neighborhood. She said she would have to wait to see how the extended hours affect noise levels before passing judgment.

“I think [the selectmen] know that if the noise increases, they will be hearing from us,” she said.

Others said they support the change.

“I think it’s an excellent idea, I think it will actually make it quieter after 12:30 a.m.,” said Peter Martell, the former longtime owner of the Lampost and Rare Duck. “I can remember when our closing time was 1 a.m. and we always had this conflict because nobody wanted to leave . . . but with that extra half hour people get tired and tend to drift out on their own.”