期間Aについて、期間Bに含まれない期間の長さを計る

Date from = getStartDate();
Date to = getEndDate();
Date upper = dateOf(5, 0);
Date lower = dateOf(22, 0);

long early = 0;
if (from.before(upper)) {
  early = upper.getTime() - from.getTime();
}
long late = 0;
if (to.after(lower)) {
  late = to.getTime() - lower.getTime();
}