Since the Emperor died suddenly, it was counted later than the actual date that he died while preparing to succeed to the Imperial throne, the period of his era continued after he died (The collections of the Imperial Household Agency, 'The record of the death of Gomomozonoin').
なお、天皇急逝のため、後継の準備の為に実際よりも後の日付で発表されたため、在位日が死亡後も続いている（宮内庁所蔵「後桃園院御凶事前後記」）。