CREATE TABLE "echo_ii_class_significant_dates" (
  "shipyard" text,
  "laid_down" text,
  "launched" text,
  "commissioned" text,
  "fleet" text,
  "status" text
);

Question: Tell me the launched for august 31, 1964
SQL: SELECT "launched" FROM "echo_ii_class_significant_dates" WHERE "commissioned"='august 31, 1964';

Question: Tell me what was commissioned december 30, 1965
SQL: SELECT "commissioned" FROM "echo_ii_class_significant_dates" WHERE "launched"='december 30, 1965';