CREATE TABLE table_63159 ("Source" TEXT, "Date" TEXT, "Jody Wagner" TEXT, "Pat Edmonson" TEXT, "Michael Signer" TEXT, "Rich Savage" TEXT, "Jon Bowerbank" TEXT, "Undecided" TEXT)

On which date did Michael Signer earn 4%?
SELECT "Date" FROM table_63159 WHERE "Michael Signer" = '4%'
SELECT "Date" FROM "table_63159" WHERE "Michael Signer" = '4%'