Season 4 of Buffy the Vampire Slayer premiered on October 5, 1999.
The fourth season of the television series Buffy the Vampire Slayer premiered on October 5, 1999, on The WB Television Network and concluded its 22-episode season on May 23, 2000. It maintained its previous timeslot, airing Tuesdays at 8:00 pm ET. Beginning with this season, the character of Angel was given his own series, titled Angel, which aired on The WB following Buffy. Various Buffy characters made appearances in Angel, including Buffy herself; Cordelia Chase, formerly a regular in Buffy, and Wesley Wyndam-Pryce, who appeared in Buffy season 3, became regulars in Angel.