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

### Instruction:
When was the Hamaoka-4 unit commercial operation date?

### Inputs:
table_name: table, columns: ['Unit', 'Reactor Type', 'Net Capacity', 'Gross Capacity', 'Construction Start', 'Grid Connection', 'Commercial Operation', 'Status']

### Response:
SELECT Commercial Operation FROM table WHERE Unit = hamaoka-4