When you copy a appointment in a schedule in the current 1.7.1 build it it throws a divide by zero error

Line 180 AppointmentActEditor

 protected void onStartTimeChanged() {
        Date start = getStartTime();
        if (start != null) {
            Date rounded = SchedulingHelper.getSlotTime(start, slotSize, false);
            if (DateRules.compareTo(start, rounded) != 0) {
                setStartTime(rounded, true);
            }
        }

In this call stack the slotsize is still set at default 0