The New Testament Greek word for the Day of Preparation is παρασκευή which is the word for "Friday." This is used in: Matt. 27:62, Mark 15:42, Luke 23:54, John 19:14; 19:31; 19:42. Also, the counting of a partial day (the "onah") requires Friday to make 3 days. This is also shown in the book of Esther. There is no question that the crucifixion occurred on Friday.
In John 18:5-6, Jesus replies that he is "I am." In Greek this is εγώ είμαι ("gh-GO EE-may," original Greek εγώ είμι). He was clearly associating himself with the Hebrew name for God.