CREATE TABLE table_30837 ("By-election" FLOAT, "Electorate" CLOB, "Date" CLOB, "Incumbent" CLOB, "Reason" CLOB, "Winner" CLOB)

When edward shaw is the winner what is the date?
SELECT "Date" FROM table_30837 WHERE "Winner" = 'Edward Shaw'
SELECT "Date" FROM "table_30837" WHERE "Winner" = 'Edward Shaw'