Based on the index, it is considered that the medieval period started in the latter half of the 11th century to the 12th century, when the shoen koryo sei was started and established, and ended in the latter half of the 16th century when the taiko kenchi, which made the shoen koryo sei extinct, was conducted.
始期は11世紀後半〜12世紀の荘園公領制形成期に、終期は荘園公領制が消滅した16世紀後半の太閤検地にそれぞれ求められる。