Seven Days was based on an idea from Kerry McCluggage, then-president of Paramount Television, who pitched it to Christopher Crowe.

Christopher Crowe combined McCluggage's pitch with his own research on Area 51 to develop the series concept.

Original cast member Sam Whipple, who played Dr. John Ballard, left the series four episodes into season three after being diagnosed with cancer, which was eventually fatal.

Sam Whipple was replaced by Kevin Christy, who played new character Andrew 'Hooter' Owsley for the remainder of the season.

Justina Vail, who played Dr. Olga Vukavitch, quit the series before the end of season three, though she agreed to film a few extra scenes to wrap up her character's arc.

Tensions within the cast, Vail's departure, and the show's low ratings all contributed to UPN's decision not to renew the series for a fourth season.

The show received poor reviews from critics, who criticized its 'flimsy' premise and violence.

Justina Vail won a Saturn Award in 2000 for her performance on the show, the only win out of six award nominations for the series.