index.js

var parse = require('../parse/index.js')

/**
 * @category Month Helpers
 * @summary Get the number of days in a month of the given date.
 *
 * @description
 * Get the number of days in a month of the given date.
 *
 * @param {Date|String|Number} date - the given date
 * @returns {Number} the number of days in a month
 *
 * @example
 * // How many days are in February 2000?
 * var result = getDaysInMonth(new Date(2000, 1))
 * //=> 29
 */
function getDaysInMonth (dirtyDate) {
  var date = parse(dirtyDate)
  var year = date.getFullYear()
  var monthIndex = date.getMonth()
  var lastDayOfMonth = new Date(0)
  lastDayOfMonth.setFullYear(year, monthIndex + 1, 0)
  lastDayOfMonth.setHours(0, 0, 0, 0)
  return lastDayOfMonth.getDate()
}

module.exports = getDaysInMonth