Question: when is final show for americas got talent
[{'answer': 'September 20 , 2017', 'provenance': [{'wikipedia_id': '51620827', 'title': "America's Got Talent (season 12)", 'start_paragraph_id': 51, 'start_character': 32, 'end_paragraph_id': 51, 'end_character': 51, 'bleu_score': 1.0, 'section': 'Section::::Finals.\n'}]}]