December 25th vs the 26th

Does anyone know why Jonbenet's death date was listed as the 25th. She would have likely died on the 26th as it was after midnight. They got home after 10 according to the ramseys. Unless she died soon as they returned which I doubt because patsy said she stayed up getting things ready for their trip and burke said he was in the basement building his gift from Christmas. So unless the Ramsey's knew it happened shortly after returning home, why would they think she died on the 25th? I always wondered that.