function differenceInBusinessDays(dirtyDateLeft, dirtyDateRight) {
  __WEBPACK_IMPORTED_MODULE_7__lib_requiredArgs_index_js__["a" /* default */](2, arguments);
  var dateLeft = __WEBPACK_IMPORTED_MODULE_2__toDate_index_js__["a" /* default */](dirtyDateLeft);
  var dateRight = __WEBPACK_IMPORTED_MODULE_2__toDate_index_js__["a" /* default */](dirtyDateRight);
  if (!__WEBPACK_IMPORTED_MODULE_0__isValid_index_js__["a" /* default */](dateLeft) || !__WEBPACK_IMPORTED_MODULE_0__isValid_index_js__["a" /* default */](dateRight)) return new Date(NaN);
  var calendarDifference = __WEBPACK_IMPORTED_MODULE_3__differenceInCalendarDays_index_js__["a" /* default */](dateLeft, dateRight);
  var sign = calendarDifference < 0 ? -1 : 1;
  var weeks = __WEBPACK_IMPORTED_MODULE_6__lib_toInteger_index_js__["a" /* default */](calendarDifference / 7);
  var result = weeks * 5;
  dateRight = __WEBPACK_IMPORTED_MODULE_4__addDays_index_js__["a" /* default */](dateRight, weeks * 7); // the loop below will run at most 6 times to account for the remaining days that don't makeup a full week

  while (!__WEBPACK_IMPORTED_MODULE_5__isSameDay_index_js__["a" /* default */](dateLeft, dateRight)) {
    // sign is used to account for both negative and positive differences
    result += __WEBPACK_IMPORTED_MODULE_1__isWeekend_index_js__["a" /* default */](dateRight) ? 0 : sign;
    dateRight = __WEBPACK_IMPORTED_MODULE_4__addDays_index_js__["a" /* default */](dateRight, sign);
  }

  return result === 0 ? 0 : result;
}
@name differenceInCalendarISOWeeks
@category ISO Week Helpers
@summary Get the number of calendar ISO weeks between the given dates.

@description
Get the number of calendar ISO weeks between the given dates.

ISO week-numbering year: http://en.wikipedia.org/wiki/ISO_week_date

### v2.0.0 breaking changes:

- [Changes that are common for the whole library](https://github.com/date-fns/date-fns/blob/master/docs/upgradeGuide.md#Common-Changes).

@param {Date|Number} dateLeft - the later date
@param {Date|Number} dateRight - the earlier date
@returns {Number} the number of calendar ISO weeks
@throws {TypeError} 2 arguments required

@example
// How many calendar ISO weeks are between 6 July 2014 and 21 July 2014?
var result = differenceInCalendarISOWeeks(
  new Date(2014, 6, 21),
  new Date(2014, 6, 6)
)
//=> 3