Even when the absolute dates are available, we have to supplement the information with relative dating.
The various methods of relative dating are; This method depends on the common observation that the height of the habitational area increases as the people continue to live at the same place.
According to this method, the upper deposits are younger and the lower deposits are older.
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.
Just as in an individual’s life, some birthdates may be so important that the whole culture chooses them as the reference point for its dating system. We are all quite familiar with the BC/AD dating system.
It uses Christ’s birth year as the zero point—all other years are based upon that one.