when was the next coach appointed after niger tornadoes fired their coach?
CREATE TABLE "managerial_head_coach_changes" (
  "team" text,
  "outgoing_manager" text,
  "manner_of_departure" text,
  "date_of_vacancy" text,
  "incoming_manager" text,
  "date_of_appointment" text
);
SELECT "date_of_appointment" FROM "managerial_head_coach_changes" WHERE "manner_of_departure"='fired' AND "team"='Niger Tornadoes';