Question: when did the battle of omaha beach start
[{'answer': 'June 6 , 1944', 'provenance': [{'wikipedia_id': '60120', 'title': 'Omaha Beach', 'start_paragraph_id': 1, 'start_character': 161, 'end_paragraph_id': 1, 'end_character': 174, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '60120', 'title': 'Omaha Beach', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 917, 'bleu_score': 0.92219118535411, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11097855648856674031}, 'section': 'Section::::Abstract.'}]}]