Daniel 1:1 says the 1st siege of Jerusalem took place in the 3rd year of Jehoiakim while Jeremiah 46:2 says it was in the 4th year.  

This video demonstrates how to reconcile this apparent contradiction in the Bible, and since Daniel used the proper counting method that it's internal evidence for a 6th BC authorship date instead of a Jewish forgery in the 2nd BC proposed by critics.