index.js 960 B

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  1. var getISOYear = require('../get_iso_year/index.js')
  2. /**
  3. * @category ISO Week-Numbering Year Helpers
  4. * @summary Get the number of calendar ISO week-numbering years between the given dates.
  5. *
  6. * @description
  7. * Get the number of calendar ISO week-numbering years between the given dates.
  8. *
  9. * ISO week-numbering year: http://en.wikipedia.org/wiki/ISO_week_date
  10. *
  11. * @param {Date|String|Number} dateLeft - the later date
  12. * @param {Date|String|Number} dateRight - the earlier date
  13. * @returns {Number} the number of calendar ISO week-numbering years
  14. *
  15. * @example
  16. * // How many calendar ISO week-numbering years are 1 January 2010 and 1 January 2012?
  17. * var result = differenceInCalendarISOYears(
  18. * new Date(2012, 0, 1),
  19. * new Date(2010, 0, 1)
  20. * )
  21. * //=> 2
  22. */
  23. function differenceInCalendarISOYears (dirtyDateLeft, dirtyDateRight) {
  24. return getISOYear(dirtyDateLeft) - getISOYear(dirtyDateRight)
  25. }
  26. module.exports = differenceInCalendarISOYears