In the natural sciences under the umbrella of natural history, Geochronology is the science of determining the absolute age of rocks, fossils, and sediments, within a certain degree of uncertainty inherent within the method used. A variety of dating methods are used by geologists to achieve this. The interdisciplinary approach of using several methods can often achieve best results. On the other hand, a granite which is dated at 259.5 +/- 0.5 Ma can reasonably safely be called "Permian", or most properly, to have intruded in the Permian.