President Trump’s private schedules, made public earlier this week, show a commander in chief with an unprecedented amount of free time, a sharp departure from predecessors who packed their days with back-to-back events.

They underscore the extent to which Trump chafes at many of the more burdensome and formal responsibilities of his office and prefers a less-structured presidency that allows him to follow his own whims and consume copious amounts of cable television.

“He seems to be on top of the news cycle every day, but what he’s doing administratively is a mystery,” said Douglas Brinkley, a presidential historian who studied President Ronald Reagan’s presidential diaries and edited a book based on them. “That leak makes it appear that he’s a president that’s only working half the time.”

Axios on Sunday published three months of Trump’s private schedules, which the news site said were leaked to it by a White House aide, with charts showing that almost 60 percent of the president’s scheduled time consists of unstructured “Executive Time.” Trump’s earliest scheduled briefings and meetings often start after 11 a.m.

Interviews with historians and a review of the schedules of recent former presidents released through their presidential libraries highlight the degree to which Trump’s sparse official schedule appears to be an anomaly.

“The Trump situation is highly unusual,” said Matthew Beckmann, a University of California at Irvine professor who has analyzed several decades of presidential daily schedules and is writing a book about how commanders in chief manage their time.

Most former presidents reported starting their mornings in the Oval Office, and adhering to a packed and highly regimented daily schedule that included briefings, ceremonial events, and meetings and phone calls with lawmakers and foreign leaders.

Reagan often started his day around 7:45 a.m. with a breakfast with first lady Nancy Reagan, before reporting to the Oval Office. He typically ended his workday relatively early in the evening.

President George W. Bush often arrived in the Oval Office before 7 a.m., and regularly packed his days with dozens of brief meetings and phone calls before retiring to bed late at night, according to diaries released by his presidential library.

President Bill Clinton was perhaps most similar to Trump in scheduling his days. His presidential schedules show large chunks of “phone and office time,’’ when Clinton would make calls, work on speeches and, sometimes, play golf. Stephanie Streett, who served as a staff scheduler during the Clinton administration, said at a 2002 event at the University of Arkansas at Little Rock that White House staff tried to give the president at least three hours of “phone and office time” each day.

President Jimmy Carter, whose schedules regularly show 16-hour working days, sought to cut down on the number of ceremonial events he attended, to devote more time to his policy goals. He took speed-reading courses to help with his consumption of more than 300 pages of official documents each day.

“The time pressures are so tremendous that every minute is valuable,” Carter wrote in his diary on Jan. 27, 1977, less than a week after he was sworn in.

President Barack Obama’s private schedules have yet to be released, but his aides said he often started his day early with exercise and intelligence briefings, and worked until dinnertime, when he would join his family for a meal. Obama has said he often took thick briefing books with him to his study for late-night cram sessions.

Not having a defined agenda can have reverberations beyond the Oval Office and throughout the West Wing, where the daily schedule is distributed widely among staffers, said Alyssa Mastromonaco, Obama’s deputy chief of staff.

“The president’s schedule is an organizing mechanism for the West Wing,” she said in an email. “Senior staff knows what to be prepared for and when, of course there are emergencies, but the point is to keep emergencies and chaos to a minimum. It’s hard to imagine the senior White House staff aren’t just sitting around, checking Twitter and waiting to be called into the Oval.”

The White House defended Trump’s use of unrestricted “executive time,” and said he often makes important calls and hosts meetings during time that is not listed on his private schedule.

“President Trump has a different leadership style than his predecessors and the results speak for themselves,’’ White House press secretary Sarah Sanders said in a statement. “While he spends much of his average day in scheduled meetings, events, and calls, there is time to allow for a more creative environment that has helped make him the most productive President in modern history.’’

The leak itself was described by current and former officials as a massive betrayal, the latest sign that there are people working in the White House who are actively undermining the president.

Madeleine Westerhout, the White House director of Oval Office Operations, called the leak “a disgraceful breach of trust” in a tweet.

Former Trump aides who have written tell-all books or spoken publicly describe a president who is averse to the more structured and studious responsibilities of his office.

“He hated the intel briefings. Anything that was cerebral, he hated,” said Omarosa Manigault Newman, a former senior White House aide who had a public falling-out with Trump after she was fired. “They used to sandwich those between other events that he found more enjoyable. Now, it’s as if they have just given up on any way for him to appear presidential.”

In a book titled “Team of Vipers,” former communications aide Cliff Sims wrote that Trump disliked lengthy briefings, and preferred compact charts and graphs to lengthy prose. The president once walked out of a meeting with then-House Speaker Paul D. Ryan (R-Wis.) to watch television after Ryan spent 15 minutes discussing health-care policy, according to the book.

Sims wrote that Trump’s official schedule in the early months of his presidency was “kind of a suggestion, more of a loose outline than something to which everyone paid close attention.”

In a December interview with CBS News’s Bob Schieffer, former secretary of state Rex Tillerson said Trump is an impulse-driven president who “doesn’t like to read, doesn’t read briefing reports, doesn’t like to get into the details of a lot of things.’”

After Tillerson’s comments circulated on cable news, Trump shot back on Twitter, calling his former top diplomat “dumb as a rock.”

The amount of time the president spends watching cable news and tweeting has vexed lawmakers who are often asked to respond to Trump’s incendiary missives.

Even Republican lawmakers, including the top two Republicans in the Senate, have publicly called on Trump to tweet less.

But some presidential scholars see virtue in “executive time,” given the highly demanding responsibilities of the presidency. Both Brinkley and Beckmann said Trump’s lightly apportioned schedule doesn’t necessarily mean that the president is lazy or working less than his predecessors.

“We shouldn’t fetishize hours logged or other measures of busyness,” Beckmann said. “You need time to stop and think and reflect and eat and laugh — and even watch TV.”