In fact, the tree rings can and do give an exact date, as well as age that the trees were cut.
Crossdating - The Basic Principle of Dendrochronology
www.ltrr.arizona.edu/lorim/basic.html
Crossdating is the most basic principle of dendrochronology. Crossdating is a technique that ensures each individual tree ring is assigned its exact year of formation. This is accomplished by matching patterns of wide and narrow rings between cores from the same tree, and between trees from different locations.
http://www.ltrr.arizona.edu/lorim/basic.html
ahh, excellent point.... I wasn’t speaking from knowledge (obviously) and try not to do that!! I was thinking that they would not know independently when the logs were cut down, but of course they can compare with live trees of the same species in the local area to date the rings. Thanks.