What does it matter? He didn't say that, he said "it was the day of Preparation for Passover" (except he said it in Greek, of course).
It matters because if he had said "Friday of Passover week" it would be written, "Paraskeví [Friday] tou [of] Páscha [Passover] evdomádas [week]", according to google translate.
If Passover week is abbreviated to just "Passover", you get exactly what John wrote, in the Greek.
If you type into google translate, "day of preparation for Passover" you get something quite different.