85. Getting the number of quarters between two dates

This is just another problem that requires us to have a deep grasp of the Java Date/Time API. This time, we talk about java.time.temporal.IsoFields, which was introduced in Problem 73. One of the ISO fields is QUARTER_YEARS, which is a temporal unit representing the concept of a quarter-year. So, having two LocalDate instances, we can write this:

public static long nrOfQuarters(
    LocalDate startDate, LocalDate endDate) {
  return IsoFields.QUARTER_YEARS.between(startDate, endDate);
}

Feel free to challenge yourself to provide a solution for java.util.Date/Calendar.