The dating of remains is essential in archaeology, in order to place finds in correct relation to one another, and to understand what was present in the experience of any human being at a given time and place.
On the one level, events and individuals are placed in an absolute chronology: the exact years and sometimes even months and days of the events and biographies are known.
On the other level, the exact years may not be known, but it is known that one feature is earlier or later in relation to another; this is typically the case on an excavation, where the different archaeological strata allow objects found to be placed in a relative historical framework.
For a long period in the 20th century Egyptian and Near Eastern chronology seemed to be the earliest of absolute chronologies, and imports from these areas were used to reconstruct the chronology of European prehistory.
With the introduction of objective quantifiable methods such as dendrochronology and Carbon-14 dating, over the past half century, European and North American archaeology have developed independent and more reliable chronologies, that often make it possible to date more precisely than in Egypt. For Egypt absolute year dates can only be established back to the beginning of the Late Period, from links to Greek chronology, and then from Assyrian king-lists and other Near Eastern sources, back to the Ramesside Period (still debated). The Egyptians dated by the year of reign of the king on the throne (for example 'year 3 of king X').
If we knew the precise length of reign for every Egyptian king, chronology would be no problem.