Historians, for example, know that Shakespeare's play Henry V was not written before 1587 because Shakespeare's primary source for writing his play was the second edition of Raphael Holinshed's Chronicles, not published until 1587.
Thus, 1587 is the post quem dating of Shakespeare's play Henry V.
In such cases subjective element cannot be ruled out.
The designations BC and AD deserve a brief explanation at this point.Several dating methods exist, depending on different criteria and techniques, and some very well known examples of disciplines using such techniques are, for example, history, archaeology, geology, paleontology, astronomy and even forensic science, since in the latter it is sometimes necessary to investigate the moment in the past in which the death of a cadaver occurred.Relative dating methods are unable to determine the absolute age of an object or event, but can determine the impossibility of a particular event happening before or after another event of which the absolute date is well known.All of us tend to use the most significant dates in our lives as reference points for all the others.For example, we think of our age in reference to the year we were born, and while we may give names to wedding anniversaries (silver, gold, etc.), we determine them by counting from the year of the marriage.