Вы можете использовать что-то вроде этого:
public static void main(String[] args) {
Calendar cal1 = Calendar.getInstance();
cal1.set(2011, 10, 10, 12, 00, 00);
Date datenow = cal1.getTime();
Calendar cal2 = Calendar.getInstance();
cal2.set(2011, 10, 14, 15, 00, 00);
Date datethen = cal2.getTime();
// check for weekends
long daynow = TimeUnit.MILLISECONDS.toDays(datenow.getTime());
long daythen = TimeUnit.MILLISECONDS.toDays(datethen.getTime());
long daydiff = daythen - daynow;
long weekenddiff = daydiff / 7; // number of weekends
if (cal1.get(Calendar.DAY_OF_WEEK) > cal2.get(Calendar.DAY_OF_WEEK)) {
weekenddiff++;// we have a weekend but not another full week;
}
long secDiff = TimeUnit.SECONDS.convert(16, TimeUnit.HOURS);
long weekendAdditionalSecDiff = TimeUnit.SECONDS.convert(16, TimeUnit.HOURS); // 16 additional hours for the weekend
// 16 non-work hours between two shifts
daydiff *= secDiff;
daydiff += (weekenddiff * weekendAdditionalSecDiff);
long workDiffSeconds = TimeUnit.SECONDS.convert(
datethen.getTime() - datenow.getTime(),
TimeUnit.MILLISECONDS) - daydiff;
System.out.println("Difference in working hours is "
+ workDiffSeconds + " seconds");
System.out.println("Difference in working hours is "
+ TimeUnit.HOURS.convert(workDiffSeconds, TimeUnit.SECONDS) + " hours");
}
, который сначала вычисляет количество дней между вашими днями и вычитает количество нерабочих-секунд-секунд из реальной разницы.
В выходные дни добавляется 8 дополнительных нерабочих часов в день.