Question: when was the eight hour work day established
[{'answer': '19 May 1869', 'provenance': [{'wikipedia_id': '2100109', 'title': 'Eight-hour day', 'start_paragraph_id': 50, 'start_character': 3, 'end_paragraph_id': 50, 'end_character': 14, 'bleu_score': 1.0, 'section': 'Section::::North America.:United States.\n'}]}, {'provenance': [{'wikipedia_id': '2100109', 'title': 'Eight-hour day', 'start_paragraph_id': 50, 'start_character': 0, 'end_paragraph_id': 50, 'end_character': 85, 'bleu_score': 0.861173529963367, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 5233330217138407169}, 'section': 'Section::::North America.:United States.\n'}]}]