FAQ

The film is "Legends", so no, as it doesn't belong to the body of Lucasflim-owned work designated as canon by the Lucasfilm Story Group. (Prior to the change in designation, the particular work was "continuity canon" which was regarded as less canon than the Lucasfilm-made, live-action, ordinal Star Wars films but canon nonetheless.) However, the film has not been retconned, so there hasn't been a change in continuity with other Lucasfilm "Star Wars" works, whether canon or "Legends".

According to Lucasfilm, it takes place three years after the Battle of Yavin which was in Star Wars: Épisode IV - Un nouvel espoir (1977), while L'Empire contre-attaque (1980) also takes place three years after the Battle of Yavin, and Le Retour du Jedi (1983) is set four years after the Battle of Yavin, so chronologically it takes place around the same time as The Empire Strikes Back.