It has been a year since PBS launched "Daniel Tiger's Neighborhood," a next-generation animated series about the children of characters from the Neighborhood of Make-Believe in the Pittsburgh-produced classic "Mister Rogers' Neighborhood."

"DTN" marks its first birthday today with a new episode, "Neighbor Day" (11 a.m., WQED-TV), about residents cheering one another on and celebrating their neighbors. Trolley even gets decorated in yellow flowers.

It's also the first time the show, based on characters created by the late Fred Rogers, has offered a single story across its half-hour episode; usually there are two stories per episode with a live-action filmed-in-Pittsburgh segment in between.

"It's very Fred-ish," said series creator and executive producer Angela Santomero of the neighbors theme. "We have a few themes we've identified as special and deserving of the full half-hour treatment."

A holiday story about "Snowflake Day" in December will also get a half-hour. And an episode next September about Daniel's parents having a new baby may also get the longer run time.

Ms. Santomero estimates that 30 of the 40 episodes in the show's initial order have now aired. She said she's currently developing stories for another 25 half-hours that will likely begin rolling out next September; a PBS representative confirmed that discussions about a second season are ongoing.

Ms. Santomero, a veteran children's television producer of "Blue's Clues" and "Super WHY!," said she's most surprised with the brand awareness that's developed for "DTN."

"When I went through customs in Canada, the customs guy knew the show, and people talk specifically about the strategies on the show and how amazed they are that they're working with their own kids," she said. "We have the research -- we test it to know these strategies work -- but to hear it so wholeheartedly from parents who are thankful for what we're doing has been a great fringe benefit of being on the air."

"Daniel Tiger's Neighborhood" continues to be a Top 10 hit among its target demo (children ages 2-5), and it's especially popular (No. 2) among mothers who watch TV with their children. In addition, the show is an online streaming sensation with more than 39 million streams in July alone.

Merchandise from the series will begin to arrive in stores this month, exclusively at first in Toys R Us locations. Action figures, play sets and plush versions of Daniel and friends will be available by Sept. 15, and while Fred Rogers always tried to limit the amount of merchandising from his series, the "DTN" products seem appropriate and less controversial than allowing the use of one of Rogers' songs in a Canadian Target commercial, which happened earlier this year.

Books based on "DTN" episodes are also in the works from Simon & Schuster and are expected to be in stores later this fall.

First Published: September 2, 2013, 8:00 a.m.