Trump has built his schedules around long blocks of "executive time" - unstructured periods in the day where the president's schedules show no official meetings. He often spends this time watching TV, tweeting, holding impromptu meetings and making phone calls, aides have said. Donald Trump drives a golf buggy on his golf course in Turnberry, Scotland. Credit:AP The news outlet Axios examined three months of Trump's schedules, and found that "Executive Time" accounted for 60 per cent of his scheduled hours. Axios said that Trump usually did not leave his residence for the Oval Office until about 11am. Trump has responded that he uses the time productively. "When the term Executive Time is used, I am generally working, not relaxing," he tweeted shortly after the Axios report. The White House official said Trump has not used his new golf simulator during executive time - or at all since it was put in.

Trump has played golf - the traditional kind, on an outdoor course - about 139 times as president, largely at his own golf clubs, according to an analysis by The Washington Post. There is no way to have an exact count because he usually does not acknowledge having played. Trump criticised Obama for his frequent golfing. President Barack Obama waves from a golf cart in 2015. Credit:AP But this winter, as Trump's demand for a border wall triggered a month-long government shutdown, Trump stayed off the golf course for about 69 days, the longest such period of his presidency. Trump broke the streak on February 2, playing with golf legends Tiger Woods and Jack Nicklaus at Trump's course in Jupiter, Florida. Trump complained to friends during the shutdown that he missed Mar-a-Lago and being at his Florida golf course. The White House has a long history of changes made to suit presidential hobbies. Dwight Eisenhower put in a putting green. Richard Nixon added a bowling alley. Obama turned an existing tennis court into a full basketball court and added his own golf simulator. One former aide to Obama called it "fairly unsophisticated" on Tuesday, but did not provide more details.

Loading Trump - then a businessman and conservative celebrity - repeatedly criticised Obama for spending too much of his presidency playing golf. "Can you believe that, with all of the problems and difficulties facing the US, President Obama spent the day playing golf?" Trump wrote on Twitter in October 2014. As president, however, Trump has played golf more often than Obama did: Obama played about 38 rounds a year, versus about 70 per year for Trump. That's just the outdoor kind of golf: The Post could not obtain statistics on Obama's virtual golf-playing. Trumpowns 16 golf courses. Three of them - in Jupiter, in Sterling, Virginia and in Turnberry - own simulators made by the Danish company TrackMan Golf, according to the TrackMan website. Officials at TrackMan did not respond to multiple requests for comment asking if they provided the White House's new system.

Loading The TrackMan website offers some description of how Trump's system might work: The system sold by the company includes a faux-grass mat, which serves as the tee box and fairway. It has a large flexible screens onto which a virtual golf course is projected. That system offers choices: players can play on a digital copy of the famous Saint Andrews course in Scotland, or on fictional courses made up just for the game. One offers the chance to play nine holes among "temples, volcanoes and dinosaur skeletons" in a South American jungle. Players then hit a real ball into the screen, and sensors track the speed, spin and path of the ball. Then, the computer takes over. It transforms that real shot into a virtual one, and shows the ball soaring over fairways (or dinosaur skeletons) toward the hole. When the digital ball rolls to a stop, the player re-sets with a real ball, and smacks it into the screen again.

"Feel the excitement of playing real golf on beautiful courses year round," the TrackMan website says. The system also allows players to analyse their own shots, and practice without playing on a virtual course. It says that a full set up, including the turf, screen and sensors, starts at $US49,995. How much time does it take to play a virtual round of 18 holes? About an hour if you're playing alone, according to the websites of indoor-golf businesses that rent out their TrackMan systems to visiting players. But the games can go longer: In a video posted on TrackMan's website, one customer says it takes 3 to 3 1/2hours if he plays with three friends. The Washington Post