user: Question: When is the completed date of the destroyer with a pennant number H59?
Columns: ['Ship', 'Pennant number', 'Laid down', 'Launched', 'Completed']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Gallant', 'H59', '15 September 1934', '26 September 1935', '25 February 1936']
SQL:

assistant: SELECT "Completed" FROM "Table" WHERE "Pennant number" = 'H59';