"Window of Opportunity" was the second "Stargate SG-1" script by Joseph Mallozzi and Paul Mullie, and their first episode to air. The writing duo's first script, "Scorched Earth", would air three episodes later. Choosing "Ad Infinitum" as the episode's working title, Mallozzi and Mullie originally pitched "Window of Opportunity" as a darker story from the finished episode. SG-1 would encounter a world whose scientists work feverishly on preventing an imminent apocalypse, but after being unable to find a solution in time, they initiate a time loop that would trap the SG-1 team. Executive producer Brad Wright however noted the similarities to the ' episode "Cause and Effect", and writer Robert C. Cooper suggested a lighter direction similar to the feature film "Groundhog Day", which O'Neill would briefly reference in the episode. To simplify continuity in the shooting process, Brad Wright encouraged chaos-theory-type fluctuations in the story as early as in the episode's concept meeting. Director Peter DeLuise asked the prop department to glue the Froot Loops to O'Neill's breakfast spoon to have the same loops in the same spots in each take.