The Greeks consider the first Olympic Games as the beginning or 776 BC.
The Muslims count the Prophet’s departure from Mecca, or the Hegira, as their beginning at AD 662.
The Mayan calendar used 3114 BC as their reference.
More recently is the radiocarbon date of 1950 AD or before present, BP.
In a stratigraphical context objects closer to the surface are more recent in time relative to items deeper in the ground.
Although relative dating can work well in certain areas, several problems arise.
For example, Christian time counts the birth of Christ as the beginning, AD 1 (Anno Domini); everything that occurred before Christ is counted backwards from AD as BC (Before Christ).
Radiocarbon dating is especially good for determining the age of sites occupied within the last 26,000 years or so (but has the potential for sites over 50,000), can be used on carbon-based materials (organic or inorganic), and can be accurate to within ±30-50 years.
Probably the most important factor to consider when using radiocarbon dating is if external factors, whether through artificial contamination, animal disturbance, or human negligence, contributed to any errors in the determinations.
Spiritually advanced cultures were not ignorant of the principles of mathematics, but they saw no necessity to explore those principles beyond that which was helpful in the advancement of God realization.
date of organic material - but an approximate age, usually within a range of a few years either way.