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

### Instruction:
How many original air dates were there for episode 17?

### Inputs:
table_name: table, columns: ['No. in season', 'No. disc', 'Title', 'Directed by', 'Written by', 'Original air date']

### Response:
SELECT COUNT Original air date FROM table WHERE No. in season = 17