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Mayor Gavin Newsom during a news conference Sept. 2, 2010 in San Francisco

Outgoing San Francisco Mayor Gavin Newsom, the lieutenant governor-elect, announced on Friday a belated date for his inauguration party that all but confirmed his intent to delay his swearing in to statewide office.

In a terse announcement Friday, Newsom set his celebration event in the state capitol’s rotunda for 1 p.m. on Jan. 10. Newsom and his family will greet members of the public in his new office following the event. Still, it remains unclear when, exactly, Newsom intends to hold the actual inauguration.

“This event is the official inaugural celebration,” Newsom’s campaign staff noted in a press release. “Lt. Governor-elect Newsom will be formally sworn into office on or before this date.”

The timing of Newsom’s inauguration critically determines whether the outgoing, left-leaning Board of Supervisors — whose majority has had a fraught relationship with the mayor — or the new board will appoint Newsom’s successor.

The outgoing board, currently on recess, will convene for a final session on Jan. 4, one day after Newsom’s fellow statewide officers, like Gov.-elect Jerry Brown and Attorney General-elect Kamala D. Harris, are scheduled to take their oaths of office. By delaying his own swearing in by several days, Newsom would effectively keep his seat occupied until the new board could appoint what he hopes will be a more favorable successor.

For months, Newsom has equivocated on the issue. As recently as November, the mayor said that he was “99 percent sure” that he would relinquish his seat on Jan. 3, though news reports have for weeks indicated that he would delay his departure by several days.