30 lines
858 B
JavaScript
30 lines
858 B
JavaScript
var parse = require('../parse/index.js')
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/**
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* @category Year Helpers
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* @summary Get the number of calendar years between the given dates.
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*
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* @description
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* Get the number of calendar years between the given dates.
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*
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* @param {Date|String|Number} dateLeft - the later date
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* @param {Date|String|Number} dateRight - the earlier date
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* @returns {Number} the number of calendar years
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*
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* @example
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* // How many calendar years are between 31 December 2013 and 11 February 2015?
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* var result = differenceInCalendarYears(
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* new Date(2015, 1, 11),
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* new Date(2013, 11, 31)
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* )
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* //=> 2
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*/
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function differenceInCalendarYears (dirtyDateLeft, dirtyDateRight) {
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var dateLeft = parse(dirtyDateLeft)
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var dateRight = parse(dirtyDateRight)
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return dateLeft.getFullYear() - dateRight.getFullYear()
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}
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module.exports = differenceInCalendarYears
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