code: public static int truncatedCompareTo(final Calendar cal1, final Calendar cal2, final int field) {
          final Calendar truncatedCal1 = truncate(cal1, field);
          final Calendar truncatedCal2 = truncate(cal2, field);
          return truncatedCal1.compareTo(truncatedCal2);
      }
docs: Determines how two calendars compare up to no more than the specified
  most significant field.
  
  @param cal1 the first calendar, not <code>null</code>
  @param cal2 the second calendar, not <code>null</code>
  @param field the field from {@code Calendar}
  @return a negative integer, zero, or a positive integer as the first
  calendar is less than, equal to, or greater than the second.
  @throws IllegalArgumentException if any argument is <code>null</code>
  @see #truncate(Calendar, int)
  @see #truncatedCompareTo(Date, Date, int)
  @since 3.0