CREATE TABLE table_39483 ("Date" CLOB, "Tournament" CLOB, "Winning score" CLOB, "Margin of victory" CLOB, "Runner ( s ) -up" CLOB)

What day was the margin of victory 1 stroke when the tournament was colonial national invitation?
SELECT "Date" FROM table_39483 WHERE "Margin of victory" = '1 stroke' AND "Tournament" = 'colonial national invitation'
SELECT "Date" FROM "table_39483" WHERE "Margin of victory" = '1 stroke' AND "Tournament" = 'colonial national invitation'