A scientific date is either absolute (specific to one point in time) or relative (younger or older than something else). Dendrochronology, or tree-ring dating, provides absolute dates in two different ways: directly, and by calibrating radiocarbon results.

How are living trees dated?

Dendrochronology (or tree-ring dating) is the scientific method of dating tree rings (also called growth rings) to the exact year they were formed. A trees growth rate changes in a predictable pattern throughout the year in response to seasonal climate changes, resulting in visible growth rings.