The first deadline in the purported ransom note for Nancy Guthrie’s return would trigger, if missed, a change in demand, according to TMZ – who received a copy of the letter.

Law enforcement officials in Pima County confirmed at a Thursday press conference that the note “made a demand” for 5 p.m. local time with a “second demand” set for Feb. 9.

TMZ, one of the outlets that obtained the ransom note demanding millions of dollars in bitcoin for Nancy’s safe return, reported that the “demand” would change if Thursday’s deadline isn’t met.

Follow The Post’s live updates on Savannah Guthrie’s missing mom

If the supposed ransom isn’t fulfilled by Monday, then there will be “a more serious consequence,” the outlet reported, citing the note. 

The letter also highlighted insider details about Nancy’s suspected abduction, including about her Apple Watch and a floodlight at her million-dollar Tucson home. 

The note, though, didn’t list any means of contact with its authors, but it did include a real address where the ransom could be deposited.

Police have still not said whether they believe the note is real or a fraud.

Authorities are taking the note seriously, but admitted there’s an “absolute possibility” that Nancy’s disappearance has nothing to do with the ransom note.

Reporters with TMZ confirmed that they “made an agreement” with the FBI and Pima County Sheriff’s Office to “not disclose” certain details from the notes “for the sake of the investigation.” 

The outlet claimed that authorities are taking the ransom note “seriously” in part due to certain unspecified “characteristics” that led them to believe “these people are serious and they actually do have Nancy.”

Nancy, the 84-year-old mother of “Today” show host Savannah Guthrie,  was reported missing on Sunday after she missed morning mass at her local church.

Savannah and her siblings, Annie and Cameron, shared a heart-wrenching video Wednesday evening telling the suspected abductors that they are “ready to talk” – but only once they know their mother is alive.

“We need to know, without a doubt, that she is alive, and that you have her. We want to hear from you, and we are ready to listen. Please, reach out to us,” Savannah said in a tearful statement.

Police confirmed that splotches of Nancy’s blood were found at her home, where she was last seen Saturday evening after a night out with Annie and her son-in-law. 

Sources told The Post on Wednesday that the investigation pivoted to probing people who know Nancy.

As of Thursday, authorities still hadn’t ruled out Nancy’s son-in-law, the last person who saw her Saturday evening, as a possible suspect.