Sean Spicer, Donald Trump’s first White House press secretary and a Harvard politics fellow, came under fire on Wednesday for a tweet in which he appeared to confuse one major second world war anniversary for another.

Spicer wrote: “Today is Dday [sic]. It only lives in infamy if we remember and share the story of sacrifice with the next generation. #DDay.”

7 December is indeed an important second world war anniversary – that of the Japanese attack on Pearl Harbor, Hawaii, which brought the US into the war.

Pearl Harbor has been called many things, including most famously “a date which will live in infamy” by the then president, Franklin Delano Roosevelt.

But not D-day. That was 6 June 1944, when allied navies sent forces ashore in France, the start of the end of the war against Nazi Germany.

Pearl Harbor was primarily an attack on the US navy. According to US government figures, 2,008 members of the navy were killed, along with 218 members of the army, 109 marines and 68 civilians. Nineteen ships were destroyed or damaged.

According to his own website, Spicer “holds a master’s degree in national security and strategic studies from the US Naval War College [and] has served over 20 years in the US navy reserve and is currently a commander”. He specialises in public affairs.

On Wednesday, amid a minor PR nightmare and Twitter storm, Spicer deleted his D-day tweet and said: “Sorry. Apologies.”

Undeleted was a tweet from 2021 in which Spicer showed he knew when D-day was and was happy to use that knowledge to attack Joe Biden, writing: “Yesterday was the anniversary of #DDay – no mention of it from the president. The White House press secretary says he might get around to it.”

Biden was widely attacked from the right for not formally marking D-day last year.

But as the fact-checking website Snopes put it: “While neither Biden himself nor the White House, as such, publicly commemorated the 77th anniversary of D-day in 2021, Vice-President Kamala Harris and first lady Jill Biden both did.”

Furthermore, “in his speech at Arlington National Cemetery on Memorial Day, 31 May, Biden briefly alluded to the D-day landings, saying: ‘Here in Arlington lie heroes who gave what President Lincoln called ‘the last full measure of devotion’. They did not only die at Gettysburg or in Flanders Fields or on the beaches of Normandy, but in the mountains of Afghanistan, the deserts of Iraq in the last 20 years’.”

On Wednesday, the Associated Press said a “dwindling number” of Pearl Harbor veterans returned to Hawaii to mark the 81st anniversary of the Japanese attack.

Ira Schab, 102, was on the USS Dobbin as a tuba player in the ship’s band. He remembered seeing Japanese planes flying overhead and wondering what to do.

“We had no place to go and hoped they’d miss us,” he said, also describing how he fed ammunition to machine gunners on the vessel, which was not hit.

Of the remembrance ceremony, Schab said: “I wouldn’t miss it because I got an awful lot of friends that are still here that are buried here. I come back out of respect for them.

“Remember what they’re here for. Remember and honor those that are left. They did a hell of a job. Those who are still here, dead or alive.”

• Associated Press contributed reporting