AMC will be taking an especially close look at delayed-viewing ratings for the “The Walking Dead,” whose midseason premiere Sunday in the middle of a holiday weekend produced below-par same-day numbers — even if it remains television’s gold standard among scripted series in key demos. Over at HBO, meanwhile, it was a quiet start for period music drama “Vinyl” on the same night.

Looking at Nielsen’s “live plus same-day” estimates released this morning, the zombie drama averaged a 6.8 rating in adults 18-49 and 13.7 million viewers overall — down 15% in the demo and 12% in total viewers from last year’s comparable premiere episode (which aired the week before the Presidents Day holiday). Even at this same-day demo level, though, Sunday’s hour of “Dead” out-rates every episode this season of top broadcast scripted series “Empire” and “The Big Bang Theory.”

Following “The Walking Dead,” the season premiere of “Talking Dead” had a very strong showing (3.1 rating in 18-49, 6.44 million viewers overall), outdrawing all eight episodes from last fall.

In addition to the distractions offered up by a three-day weekend, the midseason premiere of “The Walking Dead” also took place on Valentine’s Day. And it had plenty of competition across the dial, including Valentine’s Day specials on both ABC (“The Bachelor”) and NBC (“The Tonight Show”), the NBA All-Star Game on TNT and TBS and the basic-cable premiere of “Frozen” on Disney Channel.

At its peak, “The Walking Dead” may have been able to better withstand such a tough schedule challenge, but there have been indications over the past year that the show may actually be mortal.

“Dead’s” incredible streak of growing its ratings with each half season finally came to an end last year, when the back half of seven five (7.3 rating in adults 18-49, 14.3 million viewers overall) came in below the show’s peak stretch in the fall of 2014 for the first half of its fifth season (7.5 in 18-49, 14.6 million viewers overall). It then dipped further for the fall half of its sixth season, which averaged a 6.7 rating in the demo and 13.3 million total viewers.

On average, last fall’s episodes grew in “live plus-3” by 39% in 18-49 (to 9.3 rating) and by 36% in total viewers (to 18 million). It’s likely it will see even bigger time-shifting with Sunday’s premiere.

That’s what HBO is hoping for with regard to “Vinyl,” whose two-hour premiere Sunday drew just 764,000 viewers. The drama, which stars Bobby Canavale as a New York record executive in the 1970s, came in considerably lower than other HBO drama openers in recent years like “The Leftovers” (1.77 million), “True Detective” (2.33 million) and “The Newsroom” (2.14 million).

Review: ‘Vinyl’

A second airing of “Vinyl” at about 11:30 p.m. added 371,000 viewers.

Elsewhere on Sunday night in cable, the NBA All-Star Game hit a three-year high in viewership as a combined 7.61 million watched the contest on TNT (6.18 million) and TBS (1.43 million) and averaged a combined 3.3 rating in adults 18-49. And at Disney Channel, the network premiere of theatrical blockbuster “Frozen” drew 3.9 million viewers.