What was the date of the game with the Kansas City Royals when the Blue Jays record was 18-12?
CREATE TABLE "game_log" (
  "date" text,
  "opponent" text,
  "score" text,
  "loss" text,
  "attendance" text,
  "record" text
);
SELECT "date" FROM "game_log" WHERE "opponent"='royals' AND "record"='18-12';