What is the Date with an Opponent that is flavia pennetta?
CREATE TABLE "singles_5_5_runners_up" (
  "outcome" text,
  "date" text,
  "tournament" text,
  "surface" text,
  "opponent" text,
  "score" text
);
SELECT "date" FROM "singles_5_5_runners_up" WHERE "opponent"='flavia pennetta';