What is the earliest a team can win a title or be relegated?

A theoretical answer

A league season fascinates us in different ways. Sometimes it’s a neck-and-neck race that goes to wire — at either end, or both. Other times a team might dominate to such an extent that the question becomes: by how many games to spare will the team win the title? Similarly, at the other end of the table, relegation can be mathematically confirmed with weeks to spare.

So what is the earliest a team can be mathematically confirmed as Champion? Equally, what is the…