What is the time frame of the novel, Freak the Mighty?

The story of the two outcasts, Kevin and Max, and how they
team up to become "Freak the Mighty," takes place over the course of about one year. The
story begins the summer before the two boys enter the eighth grade when they reunite for
the first time since they were small children in day care. Max reminds the reader that
the boys had first become acquainted when they were known as "Kicker" (Max liked to kick
other kids) and "Robot Man" (Kevin wore leg braces at the time). They met briefly again
when they were in the third grade. The boys become fast friends during the summer and
the first part of the school year, after which Max is kidnapped by his father, "Killer"
Kane, at Christmas. Things return to normal for the rest of the school year, but just
after the eighth grade lets out for the summer, Kevin has a seizure on his birthday and
dies a few days later. Although no specific year is given for the story, author Rodman
Philbrick published the novel in 1998. The setting for Freak the
Mighty is Portsmouth, New Hampshire, Philbrick's home
town.