The date of his departure, in the reign of the Emperor Yuryaku, is not determined, but considering other Urashima legends, which have something in common, suggest that time of this world must had passed much faster than that of three years in the palace.
出発時の雄略天皇の代がいつなのか確定しがたいが、他の浦島伝説での共通点も踏まえ現世では館での3年より遙かに長い時間が流れていたと伝えられることは確実なようである。