Sentence:  This leads Irenaeus to the somewhat startling notion that Adam and Eve died on the same day that they disobeyed , namely , on a Friday , as a parallel to the death of Christ on Good Friday ; he sees a parallel also to the Jewish <WSD>day</WSD> of preparation for the Sabbath . 
Meaning of the word marked with <WSD> tags:  a day assigned to a particular purpose or observance