Saturday represents the last chance to drop off your ballot — and even register and vote on the same day — to make sure your vote is counted in the primary election, which is already breaking records on Oahu.

Potential voters can still register and vote at so-called “voter service centers” on all islands today and Saturday — and deposit their “mail-in” ballots at various sites across the state.

Locations can be found by visiting elections.hawaii.gov/voter-service-centers-and- places-of-deposit/.

Mail-in ballots left at “places of deposit” should be picked up in time for Saturday’s scheduled close of voting at 7 p.m. People waiting in line at a voter service center by the scheduled 7 p.m. close will still be allowed to vote, although the delay will hold up the official closing of polls.

As of Thursday, Honolulu voters had cast more than 225,000 ballots, according to city estimates. If confirmed, that number would break the city’s all-time voter turnout for a primary election, said Rex Quidilla, the city’s elections administrator.

The previous record for a Honolulu primary of 225,406 votes cast was set in 1994. Historians have to go all the way back to 1978 to find what is expected to be the third highest number of Honolulu primary votes cast, or 219,379.

“The turnout record is being broken as we speak,” Quidilla said Thursday at Honolulu Hale. “This is going to be a historic high. It’s incredible. It’s fantastic news.”

As Quidilla spoke, voters continued pulling up to Honolulu Hale to drop off their mail-in ballots or register and vote, such as Lehua Hale of Diamond Head, who re-registered after changing addresses.

“It was easy,” Hale said after stepping out of the voting booth. “They were really organized.”

Like others, Hale — who described her age as “past 70” — said it’s her duty to vote.

“You have to make a difference, right?” she said.

The early votes belied skeptics who predicted that more than 700,000 mail-in ballots sent to registered voters last month across the state would do little to increase the actual number of votes cast in an island state that traditionally lags the rest of the country in turnout.

Councilwoman Kym Pine, who is running in the crowded mayoral race, brought her husband and daughter to Honolulu Hale to cast her vote in person Thursday.

Pine brought her mail-in ballot and had to show it to election officials to prove that she was voting only once.

Before the era of mail-in voting, Pine would have voted at Ilima Intermediate School, one of 235 polling places across the state.

Asked about the high turnout of votes already cast on Oahu, Pine said she’s worried about complaints of people not receiving their ballots, voters receiving multiple ballots or voters’ signatures being challenged.

But Quidilla — who used to run the state Office of Elections — said there can be simple explanations for problems with mail-in voting often cited on social media, such as ballots sent to old addresses and second ballots sent to new addresses.

Voters with concerns and specific examples need to call the city at 768-3800 to “to help keep the voter registry clean,” Quidilla said.

Across the islands, more than 317,000 people voted in person or turned in their mail-in ballots by Wednesday — including Oahu voters, said Nedielyn Bueno, spokeswoman for the state Office of Elections.

“That’s a big number,” Bueno said. “It’s showing that people want to participate.”

On Oahu, the marquee race on Saturday will decide who will become Honolulu’s next mayor outright by winning a simple majority — or which candidates will move on to a runoff in November’s general election, which also will decide America’s next president.

On Saturday the first election returns after the polls close at 7 p.m. are scheduled to include all of the ballots cast by mail or left at drop boxes statewide through Friday, Bueno said. The second returns — around 10 p.m. — are expected to include walk-in votes cast at voter service centers and mail-in ballots collected by 7 p.m. Saturday, she said.

The final election returns are expected to come in early Sunday morning.

Even though there are no longer 235 polling sites to account for, Bueno said the great unknown Saturday is “we don’t know what the volume’s going to be like on election day.”

Barbara Abrew, 70, a McKinley High School English teacher, appreciated the time to study her ballot, which she finally dropped off at Honolulu Hale on Thursday with her dog, Sembei, along on a leash.

Abrew ran out of time to mail in her ballot and make sure it arrived on election night on time.

So she liked knowing that she could hand deliver it.

“I wasn’t sure about the candidates,” Abrew said. “I needed the time.”