At the time of Jesus, there was no such Jewish term as “day of Preparation” in Jewish usage. Strangely, virtually the only time that term appears in any literature from that era, it is, for all practical purposes, only from texts written by the four gospel authors, or, perhaps, from someone quoting the gospel sources. But it is not independently attested outside of the gospel sources, a good indication that this was not actually a Jewish term.
A great article on the Roman and Jewish calendars. Read the whole article here. You won’t regret it