"Rock Center" will air Wednesdays at 9 p.m. Eastern time, an hour earlier than its previous slot. From the show's Halloween premiere last fall through the end of January, it was shown on Monday nights.
The network's plan from the beginning was to move the show around until it found the right spot for it, said David Corvo, senior executive producer at NBC News.
"I would be surprised if we didn't move again before the summer's over," he said.
The show has struggled to find an audience since its attention-getting start with Bob Costas' interview of former Penn State football assistant coach Jerry Sandusky, who's accused of sexually assaulting boys. It's averaging 3.9 million viewers this season. Even that number is slightly inflated, since a two-hour GOP presidential debate that aired in January before 7.1 million people was labeled "Rock Center" so its higher ratings could be included in the newsmagazine's Nielsen averages.
Six of the last 10 "Rock Center" episodes failed to reach 3 million viewers, the Nielsen ratings company said.
Williams' "Nightly News" gets more than twice as many viewers as his newsmagazine does in prime time, when more people are watching television.
Horizon Media research analyst Brad Adgate said the "Rock Center" numbers are "pretty disappointing."
Corvo said it takes time for a newsmagazine to become established and NBC shows no interest in pulling the plug. He said the network has already committed to air the show next season.
"We didn't get into it without understanding that it's a long-term play," he said.
Even television's most established and popular newsmagazine, CBS' "60 Minutes," took time to get started, he said. "60 Minutes" began as a Tuesday night show in 1968 before shifting to Sundays three years later, but it wasn't until 1975 that it began airing year-round.
Compared with comedies or dramas, newsmagazines are relatively inexpensive for a television network to make, lessening the financial pressure to air a higher-rated show. And it's not like NBC is dealing from a position of strength: The Thursday night comedies "30 Rock," "The Office" and "Up All Night" each had audiences of less than 3 million last week, Nielsen said.
"Rock Center" is still experimenting with the mix of stories it airs each week, and their lengths, to establish a regular rhythm, Corvo said. This week's episode features an investigation into a potential defect in rifles and shotguns, interviews with New York City ironworkers about their experiences during the past decade and a feature on concerts in living rooms.
The Costas interview with Sandusky aired Nov. 14.
Sandusky, who's 68, acknowledged he showered with young boys and hugged them but called the contact "horseplay." He said he was not a pedophile but, in retrospect, should not have showered with the boys he was charged with sexually assaulting. He awaits trial.