Apparently in the dual-reality world of “Awake,” there are no calendars.

NBC’s new drama takes the “Groundhog Day” concept quite a bit further. In the 1993 comedy, the Bill Murray character wakes up to repeated Groundhog Days, with his alarm clock radio playing “I Got You, Babe” each Feb. 2.

In “Awake,” Michael Britten begins a new day with his wife in bed beside him and his son has been killed in a car accident at the beginning of the first episode. But on other days, his wife has been killed in the wreckage and he shares his home with his son.

He appears to be living two realities, which he separates by wearing either a red or green rubber band around his wrist. On green rubber band days, his son is alive and the car crashed claimed his wife. On red rubber band days, his wife was killed in the accident and his son is alive.

But is he living two Mondays back to back — or is Monday his red reality and the following day a green reality Tuesday? It’s a nagging question that the pilot episode doesn’t answer.

The premise for “Awake,” premiering at 9 p.m. on Thursday, March 1, is complex with the two alternating lives of the main character. Even he is confused, with the red-to-green wristband switch offering a signal to what reality he is living. There’s even one morning in the pilot when Britten wakes up in great panic to find his wrist bare.

What does intrigue is the question, Is Britten bouncing between two parallel realities or is something else entirely going on? There are hints that more surprises are in store as Britten continues to live in both of his worlds.

Jason Isaacs, best known as Draco Malfoy’s father in the “Harry Potter” film series, plays Britten, the police detective main character. Dylan Minnette is the son, Rex, and, after season six of ABC’s “Lost,” it’s not his first series as a questionably real kid. As Britten’s wife is Laura Allen, a relative TV newcomer, unless you watched the FX series, “Dirt.”

The Britten family doesn’t yet have any relatives or friends (or even neighbors?), because those relationships would further complicate the show’s premise. There is a bureau-assigned therapist in each of Britten’s realities. Cherry Jones of “24” counsels him in the green (son alive) reality and B.D. Wong, who also played a psychologist on “Law and Order: SVU,” in the red (wife alive) reality.

Britten is a detective in both of his worlds but with different partners — Steve Harris from “The Practice” and Wilmer Valderrama from “That ’70s Show.” And the overlap between the two realities helps him solve crimes in each. In the debut, evidence is found in a parking lot named Waverly with a parking space numbered 611 that resolves a child kidnapping and there’s similar information leading to a murder case being investigated at the address of 611 Waverly.

Isaacs is a great actor, but his character is single-dimensional. His co-stars appear to be having more fun in their roles.

“Awake” has been planned as a midseason entry, and the series replaces NBC’s “The Firm.” The John Grisham-inspired legal drama will make way for “Awake” on Thursday nights by moving to Saturday for the remainder of its run.

The success of “Awake” hinges on the ability of the creative team to extend the creative tension of the premiere episode and lift it beyond yet another police procedural drama.