With a good knowledge of Onmyodo (way of Yin and Yang) and Tenmondo (ancient astrology), he marked the beginning of kakumeikanmon and Shinyukaigen by proposing to change the name of the era to 'Engi,' noting that the year 901 was the year for Shinyu-kakumei (revolution in Kanototori of the Chinese astrological calendar) according to Shinisetsu.
陰陽道天文道に明るく、昌泰4年（901年）は讖緯説による辛酉革命の年に当たると指摘、「延喜」と改元することを提唱して革命勘文・辛酉改元の端緒を開く。