Andy Cohen, Mariah Carey add zing to New Year’s

For New Year’s Eve, Ryan Seacrest offers the biggest mystery while Anderson Cooper makes the biggest change.

Joining Cooper — and succeeding the fired Kathy Griffin — on CNN’s telecast will be Andy Cohen, free-spirited host of Bravo’s “Watch What Happens Live.” Pals Cohen and Cooper are witty storytellers, as they’ve demonstrated with their gossipy “AC2” stage show.

Tart and smart, they promise a diverting way to usher in 2018, starting at 8 p.m. Sunday. They’ll be based in New York’s Times Square until 12:30 a.m. Monday.

CNN will draw on Don Lemon and Brooke Baldwin in New Orleans, Bill Weir in Key West, Randi Kaye in Denver and Sara Sidner in Nashville, where Keith Urban will perform. Gary Tuchman will report from Las Vegas, but Cooper and Cohen interview Celine Dion from her stage show.

On ABC, Mariah Carey returns to “Dick Clark’s New Year’s Rockin’ Eve with Ryan Seacrest 2018.” She gave a disastrous performance last year. Can she be a hero this time?

ABC’s telecast, starting at 8 p.m., runs 5 and a half hours. Jenny McCarthy will be in Times Square, where Camila Cabello, Nick Jonas and Sugarland will sing. Britney Spears performs in Las Vegas. Lucy Hale hosts the countdown in New Orleans, where Imagine Dragons and Walk the Moon will perform.

Ciara will host ABC’s West Coast portion. Performers there include Alessia Cara, Zedd, G-Eazy, Halsey, Bebe Rexha, Florida Georgia Line, Hailee Steinfeld, Alesso, Kane Brown, Kelly Clarkson, Fitz and the Tantrums, Khalid, Shawn Mendes and Charlie Puth.

Steve Harvey steps into a new role as host of Fox Broadcasting’s special from 8 to 10 p.m., resuming at 11. He and co-host Maria Menounos will be in Times Square. They will introduce Neil Diamond, Andra Day, Maroon 5, Zac Brown Band, Macklemore and Flo Rida. Celine Dion and Backstreet Boys perform in Las Vegas.

Fox News Channel presents the two-hour “Countdown to 2018” at 8 p.m. At 10, Fox News personalities Lisa “Kennedy” Montgomery and Jesse Watters host from Times Square, and the telecast goes to 1 a.m. Kat Timpf and Richard Fowler talk to the crowd in Times Square, and Bryan Llenas reports on security. Griff Jenkins will be in Nashville, and Carley Shimkus will be in Miami Beach. Wednesday, 8 p.m. Wednesday, 9 p.m. Thursday, 9 p.m.