What day was there a hard surface when the partner was Marc Gicquel?
CREATE TABLE "doubles_6_2_4" (
  "outcome" text,
  "date" text,
  "surface" text,
  "partner" text,
  "opponents" text,
  "score" text
);
SELECT "date" FROM "doubles_6_2_4" WHERE "surface"='hard' AND "partner"='marc gicquel';