At least two Tisbury voters were denied the chance to cast ballots at the annual town elections Tuesday after officials mistakenly closed the polls approximately one minute early, Tisbury town clerk J. Hilary Conklin confirmed.

The town election Tuesday included a tight race for selectman and a ballot question regarding an extension to the town sewer. Polls were open from noon to 8 p.m. at the Tisbury emergency services facility.

Town officials in Tisbury use the clock on the ballot box as the official timepiece for the election. Town clerks are responsible for overseeing the election and the constable is responsible for closing the polls. Because Ms. Conklin was on the ballot, Oak Bluffs town clerk Colleen Morris oversaw the election, although Ms. Conklin was on hand.

Speaking to the Gazette on Wednesday, Ms. Conklin recounted the events that had taken place near closing time at the polls. She said town constable Mike Ciancio closed the polls when the ballot box read 8 p.m. According to state election guidelines, any voters who are in the process of voting, in the building, or in line when the polls are closed are entitled to complete their vote, even if the ballot is entered after the polls are closed.

Three voters were in the building when the polls closed and they were allowed to enter their votes, Ms. Conklin said. Voting finished around 8:04 p.m., according to the time listed on the ballot box. Ms. Conklin said there were no voters in line when the ballot box read 8 p.m.

“At 8 p.m., the constable did the shoutout — ‘The polls are closed,’” Ms. Conklin said on Wednesday. “I was across the room, and could see that there was no one there.”

But shortly thereafter, at least two Tisbury voters arrived at the polls looking to cast ballots, according to Ms. Conklin.

A Gazette reporter was also on the scene at the polls and observed a voter being turned away.

In an emailed letter sent to the Gazette Tuesday night, Joan Shea said she and three other voters had arrived at the polling station at 7:58 p.m., according to the time on their cell phones, but were denied the opportunity to cast ballots because Mr. Ciancio had already closed the polls. Once polls are officially closed, according to state election regulations, they cannot be reopened.

“The constable told us that the machine closed itself after the allotted time [8 p.m.]. If this is true the machine was started before noon,” Ms. Shea wrote. “If every vote counts, four votes went uncounted this evening.”

On Wednesday, Ms. Conklin confirmed that the machine had been started one minute early, and said that she had spoken to at least two voters who were mistakenly prevented from voting because the polls were closed prematurely. She apologized for the mistake and said that the town was taking steps to address it with a new timekeeping method moving forward.

“What I am now aware of is that the clock on the machine was one minute ahead,” Ms. Conklin said. “So we are changing our practice, we are changing our time keeping method going forward to eliminate this issue.”

Officials instituted extensive hygienic and social distancing regulations at the polling station on Tuesday, leading to long lines for voters throughout the day. Ms. Conklin said the state had instituted expanded early and mail-in voting options considering the unusual election circumstances, but had made no concessions for extending polling times.

Ms. Conklin said that she had been on the phone throughout the morning Wednesday with state election officials discussing ways to resolve the problem that had occurred on Tuesday night, and that they had come up with a system going forward.

“Someone is going to step outside, turn their phone back on, and use that, as opposed to the time on the machine,” the town clerk said.

She expressed apologies and regrets that there were voters who were unable to cast ballots. She said she planned to speak to them all individually.

“I’m hoping I will get a chance to talk to them to apologize,” Ms. Conklin said.

The election ended with incumbent selectman Melinda Loberg losing her seat to Larry Gomez in a surprise 422-368 vote. A $6.4 million sewer expansion overwhelmingly passed.