"Sunshine Days" is the eighteenth and penultimate episode of the ninth season of the American science fiction television series The X-Files, and the series' 200th episode overall. It originally aired on the Fox network on May 12, 2002. The entry was written and directed by executive producer Vince Gilligan, his thirtieth and last episode as writer for the series. The episode is a "monster-of-the-week" episode, a stand-alone plot which is unconnected to the mythology, or overarching fictional history, of The X-Files. "Sunshine Days" earned a Nielsen household rating of 6.2, was viewed by 6.5 million households, and 10.4 million viewers in its initial broadcast. It received mixed reviews from television critics.