When does maniac magee by jerry spinelli take place?

I have read that it is a "modern day tall tale" and since it was published in the early 1990's I am assuming they are putting the setting in that era.
Now there is no Two Mills, PA., so the author created the town, the racial tensions, and all the problems in the story. Thus fiction!
I would put it n the year it was published as the author does not give it a setting in time. Many authors do that purposefully so it will last through all time!