user: Question: What date has a Position of Back, later than 1964, and a Test debut of 1st RL Test v New Zealand?
Columns: ['Player', 'Test debut', 'Year', 'Cross-code debut', 'Date', 'Position']
Types: ['text', 'text', 'real', 'text', 'text', 'text']
Sample row: ['Dally Messenger', '2nd RU Test v New Zealand', 1907.0, 'RL Test All Golds v Wales', '1 Jan 1908', 'Centre']
SQL:

assistant: SELECT "Date" FROM "Table" WHERE "Position" = 'Back' AND "Year" > 1964.0 AND "Test debut" = '1st RL Test v New Zealand';