WASHINGTON – In a tweet a week ago, Donald Trump urged his fans to head to Washington to see him get sworn in on Jan. 20.

"Let's set the all time record!" tweeted the president-elect.

But planners who are gearing up for the big day predict that Trump will fall way short of his goal: They're estimating a crowd of roughly 800,000, fewer than half the 1.8 million people who attended President Obama's first inauguration in 2009.

"It's not even close to a record," said Jim Bendat, a California expert on presidential inauguration history, who wrote a book on the subject.

After a bitter election, Trump is headed for the White House with only 48 percent of Americans approving of the way he's handled his presidential transition.

Trump has had a tough time lining up A-list talent to perform, most recently when Italian tenor Andrea Bocelli backed out this week after his fans complained.

Even many high school bands have shown disinterest: A company that organizes trips for bands says inquiries are down by at least 50 percent compared with 2009.

"Excitement and enthusiasm levels are down this year," said Luke Wiscombe, marketing director for Music Celebrations International in Tempe, Ariz.

Still, hotels, bars and restaurants in Washington and the surrounding suburbs are hoping to do well. The new five-star Trump International Hotel on Pennsylvania Avenue is sold out. A study by George Mason University predicts a $1.4 billion infusion for the region's economy.

"The enthusiasm for Trump is far less, just because this was such a nasty political season, but this is a shot in the arm," said Stephen Fuller, the economist who conducted the study. "And it's particularly important in January, which has the lowest occupancy rates for hotels. People aren't going out to eat as much, and the weather's miserable."

Weather is always the wild card for inauguration planners.

Last January, for example, Washington was hit by a blizzard that paralyzed the city with more than 2 feet of snow. And in 1985, below-zero windchills forced President Ronald Reagan's second inauguration to be moved inside.

At the Capitol, construction is underway on the 10,000-square-foot platform Trump will stand on as he takes the oath as the nation's 45th president. It will hold more than 1,600 people, including Trump's family, former presidents, the Supreme Court, Cabinet members and nominees and members of Congress.

Always the showman, Trump and a couple of his friends have discussed the possibility of having the president-elect arrive by helicopter from New York as millions watch around the world, according to the New York Times.

But details announced so far point to a very traditional inauguration. On Wednesday, the Presidential Inaugural Committee said Trump would be in Washington a day before the inauguration to lay a wreath at Arlington National Ceremony and attend a "Make America Great Again! Welcome Celebration" at the Lincoln Memorial. The day after he's sworn in, the new president plans to go to Washington's National Cathedral for the National Prayer Service.

Trying to estimate a crowd count, particularly in advance, is a big guessing game. Planners rely on past attendance records and data from various sources, including hotel and restaurant reservations and the number of expected chartered buses.

Obama broke the previous attendance record for an inauguration, set in 1965, when 1.2 million people witnessed the swearing-in of President Lyndon Johnson.

President Bill Clinton drew a crowd of roughly 800,000 in 1993, while President George W. Bush drew smaller crowds, an estimated 300,000 for his first inauguration in 2001 and 400,000 for his second inauguration in 2005.