article_snippet.sent: May 15, May 16,  May 19 .
article_snippet.sent: August 14, August 15, August 17 .
article_snippet.sent: This is because in the months of May and June there are numbers (dates) that only occur once across the four months - namely May 19 and June 18.
article_snippet.sent: So there are now just five remaining dates - July 14, July 16, Aug 14, Aug 15, Aug 17 - and Bernard
article_snippet.sent: Because Bernard now knows the date, we can whittle the date down further to three dates by ruling out the numbers that appear in duplicate.
article_snippet.sent: However, as Bernard states that he now knows the datethe date, we can rule out July 14 or August 14.
article_snippet.sent: This leaves just three dates to chose from - July 16, Aug 15 and Aug 17.
article_snippet.sent: Given that there are two dates left in August and one in July, it has to be the July date.
article_snippet.sent: So the answer is July 16.