Task: Question Answering
Input (English): Passage: The Peterloo Massacre took place at St Peter's Field, Manchester, England, on 16 August 1819, when cavalry charged into a crowd of 60,000–80,000 who had gathered to demand the reform of parliamentary representation.
The end of the Napoleonic Wars in 1815 had resulted in periods of famine and chronic unemployment, exacerbated by the introduction of the first of the Corn Laws. By the beginning of 1819, the pressure generated by poor economic conditions, coupled with the relative lack of suffrage in Northern England, had enhanced the appeal of political radicalism. In response, the Manchester Patriotic Union, a group agitating for parliamentary reform, organised a demonstration to be addressed by the well-known radical orator Henry Hunt.
Shortly after the meeting began, local magistrates called on the Manchester and Salford Yeomanry to arrest Hunt and several others on the hustings with him. The Yeomanry charged into the crowd, knocking down a woman and killing a child, and finally apprehending Hunt. The 15th Hussars were then summoned by the magistrate, Mr Hulton, to disperse the crowd. They charged with sabres drawn, and in the ensuing confusion, 18 people were killed and 400–700 were injured. The massacre was given the name Peterloo in an ironic comparison to the Battle of Waterloo, which had taken place four years earlier.
Historian Robert Poole has called the Peterloo Massacre one of the defining moments of its age. In its own time, the London and national papers shared the horror felt in the Manchester region, but Peterloo's immediate effect was to cause the government to crack down on reform, with the passing of what became known as the Six Acts. It also led directly to the foundation of the Manchester Guardian, but had little other effect on the pace of reform. In a survey conducted by The Guardian in 2006, Peterloo came second to the Putney Debates as the event from radical British history that most deserved a proper monument or a memorial. Peterloo is commemorated by a plaque close to the site, a replacement for an earlier one that was criticised as being inadequate as it did not reflect the scale of the massacre. 
Question: On what day of what month did 18 people die at a political demonstration the Manchester Patriotic Union organized?
Output (English): 16 August.