Upvote:3
I suspect that the particular example you have quoted is from the Wikipedia article on Akhenaten.
The references provided for the two date ranges are given as
More generally, the scholarly consensus is the so-called Conventional Egyptian chronology. There are some problems with the conventional chronology, however. Most of these are relatively minor, but the source of a lot of scholarly debate.
There are also a number of alternative chronologies, intended to solve specific problems with the conventional chronology. However, to date, none of these have been widely accepted.
The Wikipedia article provides a good overview.