CREATE TABLE table_21574 ("No." FLOAT, "Date" CLOB, "Tournament" CLOB, "Winning score" CLOB, "To par" CLOB, "Margin of victory" CLOB, "Runner ( s ) -up" CLOB, "Winners share  (  $  ) " FLOAT)

When was the mcdonald's lpga championship?
SELECT "Date" FROM table_21574 WHERE "Tournament" = 'McDonald''s LPGA Championship'
SELECT "Date" FROM "table_21574" WHERE "Tournament" = 'McDonald''s LPGA Championship'