In "Gishiwajinden" (literally, an 'Account of the Wa' in "The History of the Wei Dynasty"), the distance and number of required number of days to Yamayai-koku in the same route are both described for accuracy.
『魏志倭人伝』は正確を期するため同じ行程を距離と所要日数とで二重に表記しているのであり。