CREATE TABLE table_6593 ("Locomotive" TEXT, "Delivered as" TEXT, "Entered service" TEXT, "Owner" TEXT, "Status" TEXT)

What is the Entered service date of the T413?
SELECT "Entered service" FROM table_6593 WHERE "Delivered as" = 't413'
SELECT "Entered service" FROM "table_6593" WHERE "Delivered as" = 't413'