On what date was Paulo Sousa appointed?
CREATE TABLE "end_of_season_managerial_changes" (
  "name" text,
  "club" text,
  "date_of_departure" text,
  "replacement" text,
  "date_of_appointment" text
);
SELECT "date_of_appointment" FROM "end_of_season_managerial_changes" WHERE "replacement"='paulo sousa';