Question: when did daylight savings time start in united states
[{'answer': '1967', 'provenance': [{'wikipedia_id': '480675', 'title': 'History of time in the United States', 'start_paragraph_id': 15, 'start_character': 185, 'end_paragraph_id': 15, 'end_character': 189, 'bleu_score': 1.0, 'section': 'Section::::DST 1966.\n'}]}, {'provenance': [{'wikipedia_id': '480675', 'title': 'History of time in the United States', 'start_paragraph_id': 15, 'start_character': 0, 'end_paragraph_id': 15, 'end_character': 1580, 'bleu_score': 0.962307589591012, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 18054195863801178404}, 'section': 'Section::::DST 1966.\n'}]}]