NBC builds two nights of Halloween-themed programming as the final season debut of Chuck (Fridays, 8-9 p.m. ET) and the series premiere of new drama Grimm (Fridays, 9-10 p.m. ET) will begin on Friday, October 28. Likewise, Halloween-themed episodes of NBC's Thursday-night comedies - Community, Parks and Recreation, The Office, and Whitney -- will be telecast October 27 in recognition of the holiday.

In another schedule update, Harry's Law (Wednesdays, 9-10 p.m. ET) will be showcased in a three-hour marathon of episodes on Saturday, October 8 (8-11 p.m. ET).

RELATED: Chuck Series Finale Clip

Everyone's favorite secret agent is back in the final season of the action-comedy Chuck as series star Zachary Levi (Alvin and The Chipmunks: The Squeakuel) returns as Chuck Bartowski -- a regular guy who also happens to be the government's most vital secret agent.

Grimm is a new drama inspired by the Grimm's Fairy Tales and stars David Giuntoli (Turn The Beat Around) as a Portland homicide detective who discovers that he is descended from an elite line of criminal profilers known as "Grimms" who are charged with keeping balance between humanity and ominous mythological creatures.

The critically acclaimed Community (Thursdays, 8-8:30 p.m. ET) is a smart, exuberant half-hour comedy series about a tight-knit study group at Greendale Community College. At the center of the group is Jeff Winger (Joel McHale, The Soup), who forms a study group who eventually learn more about themselves than their course work.

From Emmy Award-winning executive producers Greg Daniels (NBC's The Office, "King of the Hill") and Michael Schur (NBC's The Office, Saturday Night Live), Parks and Recreation (Thursdays, 8:30-9 p.m. ET) is an ensemble comedy that follows Leslie Knope (Amy Poehler, NBC's Saturday Night Live) a mid-level bureaucrat in the PParks and Recreation Department of Pawnee, Indiana -- and her efforts to make her quintessentially American town just a little bit more fun.

From Deedle-Dee Productions, Reveille and Universal Television comes the multi-award-winning comedy series The Office (Thursdays, 9-9:30 p.m. ET), the hilarious documentary-style look into the humorous and sometimes poignant foolishness that plagues the world of 9-to-5. The Office delves into the lives of the workers at Dunder Mifflin, a paper supply company in Scranton, Pennsylvania, and the recent hiring of the weirdly charming and manipulative Robert California (James Spader, Boston Legal).

Whitney (Thursdays, 9:30-10 p.m. ET) is a new comedy starring Whitney Cummings (Chelsea Lately) and Chris D'Elia (Glory Daze) as a happily unmarried couple living out a relationship on their own terms -- in a world that expects a more traditional approach.

For embeddable clips and full episodes from NBC shows, please visit NBC.com's official show site: NBC.com/Shows.

Please follow us on Facebook and at Twitter.