The author of the Gospel of John likely changed the chronology of Jesus' crucifixion for theological and symbolic reasons rather than historical ones.
"John" wasn't trying to confuse an audience that obviously already knew the story of Jesus. What he was doing was trying to deepen the significance by playing off of tropes and symbols.
For example, the so-called "Kelvin Star Trek" films introduced an alternate "reality" for Star Trek that reveals itself subtly, in small steps in the story, making fans who are watching feel a great sense of familiarity until a main character, the mother of Spock, dies while his home planet is destroyed--something that can't happen for Star Trek to be "Star Trek."
The Gospel of John is a similar type of work. It is not attempting to be another retelling of the Jesus story every Christian knows. This author claims to be (or know) the apostle who witnessed everything and everybody, and seems quite old. He's come to understand things from a spiritual perspective--and it's this perspective, telling readers what the "Jesus experience" means, is what he does or is trying to do--as opposed to what happened.
This is similar to Matthew. Matthew wrote what Jesus "meant" for a Jewish Christian audience, as the "New Moses." So John does the same thing, writing the story as if Jesus were the Divine "Word" in control of everything from beginning to end, a physical man with a divine meaning, not merely Jesus the Christ.
Jesus first miracle was not turning water into wine at a wedding, for instance. And Jesus could indeed be recognized (though in John, the disciples don't know who he is) after his resurrection, but these two things are obviously tied together. Think. Since the author is not being literal, he's saying "what" about his subject? Especially since he's beginning and ending his Gospel about Jesus like this...the Gospel about the Word of God.
And when the bishops closed the Christian canon of the New Testament, they purposefully placed John as the last Gospel and the Revelation to John, a book of signs, last. Why? There is a significant reason.
It all has to do with why John moved Jesus's death around. It's symbolic. The author teaches in signs and symbols. From the first "sign" at the wedding at Cana to this moment and beyond, the author sees Jesus providentially in control of his life, and the author teaches us this, even if he has to change the days, times and literal events surrounding Jesus's life to do so.
He's not playing with the events of Jesus's life. On the contrary, the author is using them to teach his audience what he knows about God.