President Joe Biden turned 80 years old Sunday, the first American president to reach that age while in office.

Joseph Robinette Biden Jr. was born in Pennsylvania on November 20, 1942.

Biden has been the oldest American president in office since he was inaugurated in 2021 — at the age of 78.

The Biden family is expected to mark the occasion with brunch at the White House hosted by first lady Jill Biden, according to the White House. Many Biden family members are in Washington, DC for the president’s oldest granddaughter Naomi Biden’s wedding, which was held at the White House on Saturday.

Biden continues to dismiss questions about his health, repeatedly reassuring people that he feels physically and mentally sound.

“I no more think of myself as being as old as I am than fly,” he said in an interview with 60 Minutes in September, telling critics of his age to “watch me.”

“I mean, it’s just not I haven’t — observed anything in terms of —there’s not things I don’t do now that I did before, whether it’s physical, or mental, or anything else,” he added.

But Americans have reason to be concerned after witnessing him fall three times while boarding Air Force One in March, falling off of his bike in June, and repeatedly appearing lost or confused on stage, or unable to properly read his speeches on his teleprompter.

Two thirds of Americans in midterm exit polls said they did not want Biden to run for reelection.

Despite criticism, Biden continues defying Americans who do not want him to run again in 2024.

The president is expected to make his final decision on whether or not he will run for reelection during the Thanksgiving and Christmas holidays while spending time with family.

“My guess is it would be early next year we make that judgment,” he said at a press conference after the midterms.

If Biden runs and wins again, he would be 82 years old on Inauguration Day and 86 by the end of his second term.

Previously the oldest American president in office was Ronald Reagan, who was 77 when his second term in office ended.