Jon Levine and Matthew Sedacca write for the New York Post about a disturbing new White House revelation.

Octogenarian President Biden has difficulty functioning outside a six-hour window of daylight, according to an alarming new report.

The 81-year-old commander in chief is prone to absent-minded gaffes and fatigue outside of the hours of 10 a.m. to 4 p.m. or while traveling abroad, White House aides told Axios in a bizarre attempt to spin his disastrous debate performance.

During the 90-minute trainwreck of a presidential debate — which kicked off five hours after the president’s peak performance window, at 9 p.m. — Biden often appeared vacant or slack-jawed, and on several occasions froze mid-thought, misspoke, or struggled to form coherent sentences. 

The shocking late-night performance escalated fears about whether Biden is capable of serving another four years. He would be aged 86 by the end of his second term. 

Biden attempted to quell voters’ concerns about his mental acuity with a much more energetic speech at a rally Friday in Raleigh, N.C. — during his more preferred time frame in the early afternoon. 

“I don’t walk as easy as I used to, I don’t speak as smoothly as I used to, I don’t debate as well as I used to,” he said to a cheering crowd in the battleground state just after 1 p.m.

“But I know what I do know: I know how to tell the truth. I know right from wrong. And I know how to do this job, I know how to get things done.” 

Despite his better daytime showing Friday, Biden has faced a slew of calls from donors and pundits to drop out of the race.

Biden, however, has refused to step aside, suggesting the party leaders will maintain their support for him as well.  Former Democrat Presidents Barack Obama and Bill Clinton have also publicly expressed their continued support.