Question: when did sunday became the seventh day of the week
[{'answer': '1988', 'provenance': [{'wikipedia_id': '54407', 'title': 'Sunday', 'start_paragraph_id': 14, 'start_character': 216, 'end_paragraph_id': 14, 'end_character': 220, 'bleu_score': 1.0, 'section': 'Section::::Position in the week.:ISO 8601.\n'}]}, {'provenance': [{'wikipedia_id': '54407', 'title': 'Sunday', 'start_paragraph_id': 14, 'start_character': 0, 'end_paragraph_id': 14, 'end_character': 220, 'bleu_score': 0.9451524926983921, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 17486607533869881800}, 'section': 'Section::::Position in the week.:ISO 8601.\n'}]}]