when does the train arriving at stamford east at 11.45 departure 
CREATE TABLE "table1_18333678_2" (
  "departure" text,
  "going_to" text,
  "calling_at" text,
  "arrival" text,
  "operator" text
);
SELECT "departure" FROM "table1_18333678_2" WHERE "arrival"='11.45' AND "going_to"='Stamford East';