index.js 1.31 KB
import getQuarter from '../getQuarter/index.js';
import toDate from '../toDate/index.js';
import requiredArgs from '../_lib/requiredArgs/index.js';
/**
 * @name differenceInCalendarQuarters
 * @category Quarter Helpers
 * @summary Get the number of calendar quarters between the given dates.
 *
 * @description
 * Get the number of calendar quarters 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 quarters
 * @throws {TypeError} 2 arguments required
 *
 * @example
 * // How many calendar quarters are between 31 December 2013 and 2 July 2014?
 * var result = differenceInCalendarQuarters(
 *   new Date(2014, 6, 2),
 *   new Date(2013, 11, 31)
 * )
 * //=> 3
 */

export default function differenceInCalendarQuarters(dirtyDateLeft, dirtyDateRight) {
  requiredArgs(2, arguments);
  var dateLeft = toDate(dirtyDateLeft);
  var dateRight = toDate(dirtyDateRight);
  var yearDiff = dateLeft.getFullYear() - dateRight.getFullYear();
  var quarterDiff = getQuarter(dateLeft) - getQuarter(dateRight);
  return yearDiff * 4 + quarterDiff;
}