When is Country of united states, and a Venue of mandalay bay resort in?
CREATE TABLE "hit_n_run_shows" (
  "date" text,
  "city" text,
  "country" text,
  "venue" text,
  "attendance" text
);
SELECT "date" FROM "hit_n_run_shows" WHERE "country"='united states' AND "venue"='mandalay bay resort';