user: Question: What is the Date of the Courtyard castle?
Columns: ['Name', 'Type', 'Date', 'Condition', 'Ownership']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Borthwick Castle', 'Tower house', '1430', 'Occupied', 'Private']
SQL:

assistant: SELECT "Date" FROM "Table" WHERE "Type" = 'Courtyard castle';