date-fns/differenceInCalendarMonths/index.js

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = differenceInCalendarMonths;

var _index = _interopRequireDefault(require("../toDate/index.js"));

var _index2 = _interopRequireDefault(require("../_lib/requiredArgs/index.js"));

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

/**
 * @name differenceInCalendarMonths
 * @category Month Helpers
 * @summary Get the number of calendar months between the given dates.
 *
 * @description
 * Get the number of calendar months between the given dates.
 *
 * ### 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 months
 * @throws {TypeError} 2 arguments required
 *
 * @example
 * // How many calendar months are between 31 January 2014 and 1 September 2014?
 * var result = differenceInCalendarMonths(
 *   new Date(2014, 8, 1),
 *   new Date(2014, 0, 31)
 * )
 * //=> 8
 */
function differenceInCalendarMonths(dirtyDateLeft, dirtyDateRight) {
  (0, _index2.default)(2, arguments);
  var dateLeft = (0, _index.default)(dirtyDateLeft);
  var dateRight = (0, _index.default)(dirtyDateRight);
  var yearDiff = dateLeft.getFullYear() - dateRight.getFullYear();
  var monthDiff = dateLeft.getMonth() - dateRight.getMonth();
  return yearDiff * 12 + monthDiff;
}

module.exports = exports.default;