user: Question: When James Rutherford is the incumbent how many dates are there?
Columns: ['By-election', 'Electorate', 'Date', 'Incumbent', 'Reason', 'Winner']
Types: ['real', 'text', 'text', 'text', 'text', 'text']
Sample row: [1882.0, 'Franklin North', '9 June', 'Benjamin Harris', 'Election declared void', 'Benjamin Harris']
SQL:

assistant: SELECT COUNT("Date") FROM "Table" WHERE "Incumbent" = 'James Rutherford';