Question: when did television started broadcasting 24 hours a day
[{'answer': 'September 2009', 'provenance': [{'wikipedia_id': '519148', 'title': 'Television in the United States', 'start_paragraph_id': 31, 'start_character': 384, 'end_paragraph_id': 31, 'end_character': 398, 'bleu_score': 1.0, 'section': 'Section::::Television channels and networks.:Broadcast television.:Other over-the-air commercial television.\n'}]}, {'provenance': [{'wikipedia_id': '519148', 'title': 'Television in the United States', 'start_paragraph_id': 31, 'start_character': 0, 'end_paragraph_id': 31, 'end_character': 1562, 'bleu_score': 0.991471020640276, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 18380724975217005687}, 'section': 'Section::::Television channels and networks.:Broadcast television.:Other over-the-air commercial television.\n'}]}]