Enforcement Rules of the Estate and Gift Tax Act Article 21

Where the decedent is declared dead by a court judgment, the period specified under Article 23 of the Act for estate tax declaration shall begin from the date such judgment is declared.
中文原文 遺產及贈與稅法施行細則第21條
本法第二十三條規定之遺產稅申報期間,如被繼承人為受死亡之宣告者,應自判決宣告之日起計算。

English translation for reference only; the Chinese text prevails. Not legal advice.