CREATE TABLE "calendar" (
  "round" text,
  "main_date" text,
  "number_of_fixtures" real,
  "clubs" text,
  "new_entries_this_round" text,
  "prize_money" text
);

Question: What was the main date of the round with 20 fixtures?
SQL: SELECT "main_date" FROM "calendar" WHERE "number_of_fixtures"=20;

Question: What were the new entries for the Semi-Finals round with fewer than 8 fixtures?
SQL: SELECT "new_entries_this_round" FROM "calendar" WHERE "number_of_fixtures"<8 AND "round"='semi-finals';