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).
The sedimentation or annual varve thickness is relatively uniform, typically 1.2 mm per yr for present conditions in Lake Suigetsu which is located near the coast of the Sea of Japan.
C y BP, laminated sediment from Lake Soppensee (central Switzerland) was dated.
The radiocarbon time scale was obtained using accelerator mass spectrometry (AMS) dating of terrestrial macrofossils selected from the Soppensee sediment.
More recently is the radiocarbon date of 1950 AD or before present, BP.
There are two techniques for dating in archaeological sites: relative and absolute dating.