CREATE TABLE table_7241 ("Date" TEXT, "Tournament" TEXT, "Winning score" TEXT, "Margin of victory" TEXT, "Runner ( s ) -up" TEXT)

What is the date of the 4 strokes margin of victory?
SELECT "Date" FROM table_7241 WHERE "Margin of victory" = '4 strokes'
SELECT "Date" FROM "table_7241" WHERE "Margin of victory" = '4 strokes'