Jimmy Fallon has taken his “Tonight Show” to Los Angeles, Orlando and Minneapolis. Now he’s going to bring it to New York’s backyard.

As part of an advertising pact with T-Mobile, NBC’s “Tonight” will hold forth from Central Park in Manhattan on Thursday, September 13. Under the terms of the deal, T-Mobile will hold a nationwide sweepstakes to send fans to New York for the special event, and the broadcast will contain some content tailored for the advertiser along with surprise celebrity guests. Fallon was expected to announce the details of the agreement and the special broadcast on Thursday’s “Tonight Show Starring Jimmy Fallon.”

“The ‘Tonight Show’ has traditionally done just one-offs for advertisers,” says Josh Feldman, executive vice president of integrated marketing and network partnerships at NBCUniversal, in an interview. “This really breaks ground.”

Madison Avenue has placed new importance on wee-hours TV  programming in recent years, and this latest agreement shines a light on advertisers’ continued interest in aligning themselves with Fallon and other late-night personalities. In March, Google was able to surf into the goings-on of CBS’ “Late Show with Stephen Colbert” by sponsoring a longer-than-usual segment of the show. In May, Volkswagen AG’s Porsche drove its Cayenne Turbo into a segment of “Carpool Karaoke” on CBS’ “Late Late Show with James Corden.”ABC’s Jimmy Kimmel often devotes show time to ad pitches.  Fallon has done science-themed segments with kids as part of a pact with General Electric, and NBC’s Seth Meyers enjoyed a week-long trip to Washington, D.C., thanks in part to a sponsorship from Amazon.

Advertisers want to reach the younger audiences that gravitate to late-night programming, and are also eager to be part of a genre that is tied heavily to the news and pop culture of the day. Marketers had been pressing NBC for bigger alliances with “Tonight,” says Feldman,  “There was a demand. People were saying, ‘Can we do more?'”

Crafting the agreement took the better part of a year, he says, all to find the right elements that would work for both advertiser and show. “We went to Jimmy’s team and said, ‘Let’s find the right way to do this. We don’t want you to feel icky about the partnership; we want you to feel really good about it.’ We would not have done this if Jimmy didn’t give his blessing on the brand.”

T-Mobile has become a bigger part of popular culture as it works to buy rival Sprint in a merger valued at $26 billion. In recent months, T-Mobile has worked to attract customers by offering free access to Netflix, and, more recently,Pandora Plus. “I love shaking things up…whether that’s disrupting the status quo in wireless or bringing the iconic Tonight Show to Central Park for the very first time,” said John Legere, T-Mobile’s CEO,  in a prepared statement.

T-Mobile has been one of the bigger sponsors of “Tonight” in recent months. The wireless carrier spent more than $2.75 million on “Tonight” in the first quarter of 2018 – more than any other advertiser during that period, according to Kantar Media, a tracker of ad spending. In 2017, T-Mobile spent more than $10.4 million on the program. Other big spenders on “Tonight” in the first quarter of this year were Merck, AbbVie, Volkswagen and General Motors’ Chevrolet.

The logistics of bringing “Tonight” to Central Park are massive. NBCU’s Feldman says the company had to rent out space there for two days, using one day to load in all the equipment. He estimated 1,000 people could attend the telecast. In the week leading up to the Central Park event, T-Mobile will build anticipation by offering opportunities to win tickets at select T-Mobile stores in New York City. Fans everywhere will be able to follow the lead-up to the special broadcast by tracking unique social content, along with other surprises to be revealed in weeks to come.

T-Mobile will also be part of a special “Tonight” broadcast slated for Veteran’s Day, which will align the telecommunications company’s military support efforts with the NBC program.