What are the timeslot(s) for broadcast on February 22, 2008?
CREATE TABLE "u_s_standard_ratings" (
  "num" real,
  "air_date" text,
  "timeslot" text,
  "rating" text,
  "share" real,
  "18_49" text,
  "viewers" text,
  "weekly_rank" text
);
SELECT "timeslot" FROM "u_s_standard_ratings" WHERE "air_date"='February 22, 2008';