Question: when did black history week become black history month
[{'answer': 'February 1970'}, {'provenance': [{'wikipedia_id': '1030599', 'title': 'Black History Month', 'start_paragraph_id': 11, 'start_character': 0, 'end_paragraph_id': 11, 'end_character': 249, 'bleu_score': 0.8851932866343851, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 3380338481038033419}, 'section': 'Section::::History.:United States: Black History Month (1970).\n'}]}]