Question: when did the us begin using daylight savings time
[{'answer': '1918', 'provenance': [{'wikipedia_id': '480675', 'title': 'History of time in the United States', 'start_paragraph_id': 2, 'start_character': 206, 'end_paragraph_id': 2, 'end_character': 210, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '480675', 'title': 'History of time in the United States', 'start_paragraph_id': 8, 'start_character': 0, 'end_paragraph_id': 8, 'end_character': 391, 'bleu_score': 0.9699161750394991, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 16031250859520510967}, 'section': 'Section::::War Time 1918 and 1942.\n'}]}]