Thread:TsukiYaksha/@comment-4576906-20160410000826/@comment-25331127-20160410010704

If not mistaken, I remember it was mentioned several times in the series, though it could be roughly calculated. Also it is hinted in the third movie, where Saya stated that he had concealed Sōunga for 700 years, which is 200 (since Inu no Taishō's death) + 500 (Sengoku period ~ modern).