The Democrat’s team is planning two separate swearing-in ceremonies Thursday — a small, private one with his family in an old subway station around midnight, followed by a large event in the afternoon that will include a public block party outside City Hall.

As a new mayor’s term begins immediately with the new year, it has been customary for the city’s incoming leaders to hold two events. Outgoing mayor Eric Adams held his initial swearing-in at Times Square shortly after the famous ball drop, while Adams’ predecessor, Bill de Blasio, took his first oath at home in Brooklyn.

For his part, Mamdani will take his initial oath at the former City Hall subway station in Manhattan — one of the city’s original stops on its subterranean transit system, known for its tiled arches and vaulted ceilings.

New York Attorney General Letitia James, a political ally and notable foe of President Donald Trump, will administer the oath of office.

The old City Hall stop was designed as the flagship station of the city’s first subway line, but was decommissioned in 1945. These days, outside of occasional guided historical tours, locals can usually only catch a glimpse of it by staying on the 6 train after its last stop downtown when it turns around to head north.

In a statement, Mamdani’s office said the choice to be sworn in at the station reflected his “commitment to the working people who keep our city running every day.”

“When Old City Hall Station first opened in 1904 — one of New York’s 28 original subway stations — it was a physical monument to a city that dared to be both beautiful and build great things that would transform working peoples’ lives,” Mamdani said.

“That ambition need not be a memory confined only to our past, nor must it be isolated only to the tunnels beneath City Hall: it will be the purpose of the administration fortunate enough to serve New Yorkers from the building above,” he said.

On Thursday afternoon, Mamdani will be sworn in again, this time by U.S. Sen. Bernie Sanders, one of his political heroes, on the steps of City Hall in a ceremony scheduled to kick off at 1 p.m. U.S. Rep. Alexandria Ocasio-Cortez, another political ally, will deliver opening remarks.

Mamdani’s transition formed an inaugural committee that includes actor John Turturro, playwright Cole Escola and writer Colson Whitehead, as well as advocates, small business owners and campaign workers who the incoming mayor’s office says have “provided perspective, guidance, and cultural sensibility” for the ceremony.

The public swearing-in will be accompanied by a block party along a stretch of Broadway leading up to City Hall. Mamdani’s office expects thousands of people to attend and says there will be performances, music and interfaith elements.