Detailed Instructions: In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.
Q: He has been on the Chrysanthemum Throne since his father Akihito abdicated in 2019 .
A:
He acceded to the Chrysanthemum Throne upon the abdication of his father , the now-Emperor Emeritus Akihito on 1 May 2019 at 00:00 local time ( 15:00 UTC ) .