Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
On which date was the position less than 4 at Piraeus?

### Inputs:
table_name: table, columns: ['Pos.', 'Mark', 'Athlete', 'Venue', 'Date']

### Response:
SELECT Date FROM table WHERE Pos. < 4 AND Venue = piraeus