Question: when did ww2 officially end for the us
[{'answer': '2 September 1945', 'provenance': [{'wikipedia_id': '32927', 'title': 'World War II', 'start_paragraph_id': 9, 'start_character': 230, 'end_paragraph_id': 9, 'end_character': 246, 'bleu_score': 1.0, 'section': 'Section::::Chronology.\n'}]}]