<p>An event is a topic that can be described by the time or date at which it happened. Long-lasting events may be described as occurring between two dates. It is sometimes appropriate to create abstract events, as collections of other events -- like <a href="">World War II</a>, or <a href="">Opposition to the Vietnam War</a>, but use your best judgment here, as some topics are surely too abstract to be considered a collection of events, like 'democracy'.</p>