Donald Trump and Hillary Clinton will face off Monday in the first of a series of presidential debates.

Here's everything you need to know.

Where: Hofstra University in Hempstead, Long Island

When: Sept. 26, 2016, at 9 p.m.

Who: "NBC Nightly News" anchor Lester Holt will moderate the debate between Clinton and Trump.

To be in the debate, each candidate had to be eligible to be president, be on the ballot in “a sufficient number of states to win a theoretical Electoral College majority in the general election,” and have earned at least 15 percent of support on average in five national polls.

While Libertarian Gary Johnson and the Green Party’s Jill Stein met the first two criteria, they did not meet the third. Based on the polls selected, Clinton received 43 percent of support, Trump received 40.4 percent, Johnson received 8.4 percent and Stein received 3.2 percent.

Format: There will be six 15-minute segments during the debate, the Commission on Presidential Debates said. The topics of the debate, chosen by Holt, are “America’s direction,” “achieving prosperity” and “securing America.” Two segments will focus on each topic, the commission said.

“The moderator will open each segment with a question, after which each candidate will have two minutes to respond,” the commission said. “Candidates will then have an opportunity to respond to each other.”

The moderator will balance any remaining time in each segment between the nominees.

Celebrity drama before the debate: Mark Cuban, the owner of the Dallas Mavericks who is an outspoken Clinton supporter, tweeted on Saturday that he would be “front row” at the debate Monday. Cuban, a vocal critic of Trump, said he was ready to watch Clinton “overwhelm” the Republican nominee at the “Humbling at Hofstra."

Following Cuban’s tweet, Trump suggested the possibility of inviting Gennifer Flowers, who had an affair with Clinton's husband, former President Bill Clinton, to the debate.

“If dopey Mark Cuban of failed Benefactor fame wants to sit in the front row, perhaps I will put Gennifer Flowers right alongside of him!” Trump tweeted on Saturday.

But Mike Pence, Trump’s vice presidential running mate, told “Fox News Sunday” that Flowers would not be in attendance.

“Donald Trump was using the tweet yesterday really to mock an effort by Hillary Clinton and her campaign to really distract attention from what the American people are going to be focused on tomorrow night, which is on the issues, on the choice that we face," Pence said.

How to watch: A number of channels will air the debate on television, including ABC, CBS, CNN, C-SPAN, FOX, MSNBC and NBC. Some of these networks will also livestream the debate on their websites.

Traffic: If you plan to be near Hofstra on Monday, here are the street closures to know ahead of time:

Closures beginning at 5:30 a.m.

Earle Ovington Boulevard from Hempstead Turnpike to Charles Lindbergh Boulevard

Charles Lindbergh Boulevard from Earle Ovington Boulevard to Westbury Boulevard

Closures beginning at noon

Hempstead Turnpike (Route 24) from Oak Street to Merrick Avenue

Oak Street from Hempstead Turnpike to Westbury Boulevard

Northbound lanes of California Avenue and Meadowbrook Place at Belmont Place

Northbound lanes of Uniondale Avenue and Manor Parkway at McKenna Place

Other restrictions

Lawrence Street will become a one way going north from Route 24 to Westbury Boulevard

Courtenay Road will become a one way going south from Route 24 to Front Street

Marvin, Walton, Gilroy and Cunningham avenues will become one way going south from Route 24

No parking on Oak Street, Lawrence Street, Courtenay Road and McKenna Place

(With Lauren Cook and Reuters)