CHICAGO — On Tuesday morning, the Auditorium Theatre in downtown Chicago was relatively quiet — not surprising given the late hours of the previous night. “ The Late Show With Stephen Colbert ” had just begun a four-night series of live shows from the venue, which is part of the Roosevelt University campus. The first episode didn’t wrap up until a little after 1 a.m. Central Time.

That’s perhaps why the Auditorium still seemed a bit dead around lunchtime — save one lone man sitting outside the theater and carrying two big backpacks. Either he was ready to wait for days until he could snag a ticket to the show, or he was a Roosevelt student who had picked that specific spot to sit and scroll his phone for hours.

Despite the major late-night talk show being planned behind its doors, pedestrians and Roosevelt students strolled past the Auditorium with little notice. Apart from a few live broadcast trucks out back and a large poster promoting “The Late Show With Stephen Colbert” in Chicago (featuring Colbert holding a Chicago hot dog), there were few visible signs that CBS’ late-night talk show franchise was about to start its second night of performances there. While attendees were instructed to form a line no earlier than 6 p.m., on Monday, fans had already begun queuing up as early as 4:45 p.m.

Naturally, this means those audience members ended up spending a total of eight hours at the Auditorium. (Hopefully, they ate beforehand.) “The Late Show” typically airs in the Central Time Zone at 10:35 p.m. (11:35 p.m. ET), but the extended duration of the first night of the Democratic National Convention altered the schedule.

President Joe Biden didn’t commence his speech until around 10:30 p.m. And by the time he concluded nearly an hour later, CBS still had a half hour of local news to air. That’s why “The Late Show” on Monday didn’t begin until around 12 a.m. CT — 1 a.m. ET.

“It was an extraordinary night and extraordinarily long,” Colbert said in his monologue. “Technically, and correct me if I’m wrong, we’ve just transitioned into the first night of the 2028 campaign.”

This did not prevent the patient crowd from getting excited and cheering when the show finally went live. “It was really rowdy, enthusiastic crowd despite the fact that we didn’t get on the air until just before 1 a.m. ET,” one production insider said.

The historic Auditorium Theatre, which initially opened its doors in 1889, boasts almost 4,000 seats. Audience members are expected to be in their seats by around 8 p.m. — and at that point, the show broadcasts the convention for people to watch as they wait. (The “Late Show” team is broadcasting live in order to react in real time to the evening’s events, so it also helps if the audience knows what Colbert is referencing in his monologue). When the DNC concludes and CBS switches to local news, that’s when “The Late Show’s” warm-up comedian appears and energizes the crowd for the show.

“The Auditorium is beautiful, historic, and enormous,” Colbert remarked in his opening, before pointing a camera towards the upper balcony section. He then had a cameraperson ready to provide a bird's-eye view of how he could barely be seen from up there. “This is the first theater I’ve ever performed in where the last row of seats comes with supplemental oxygen.”

On Monday, guests who stayed up late to join Colbert included former Sec. of State Hillary Rodham Clinton and “Veep” star Julia Louis Dreyfus. The show began with a pre-recorded segment featuring Colbert, Jennifer Hudson, Nick Offerman, Sean Hayes, Jason Sudeikis, Robert Smigel and George Wendt presenting their take on Chicago through a tongue-in-cheek “Chicago National Anthem.”

Live episodes continue on Tuesday with guests including former Speaker Nancy Pelosi, House Democratic Leader Hakeem Jeffries and a special appearance by Laura Benanti, who frequently portrays Melania Trump on the show. Wednesday will feature Sec. of Transportation Pete Buttigieg and a performance by Chicago's Chance the Rapper. And then on Thursday, after Kamala Harris delivers her speech accepting the Democratic presidential nomination, “The Late Show” will go live with Rep. Alexandria Ocasio-Cortez (D-N.Y.) and a performance by Mavis Staples and Jeff Tweedy.

With reports circulating that speakers have been asked to limit their remarks during Tuesday's DNC, perhaps “The Late Show” will commence on time — or at least before midnight.