text: var staticDayTime = require('../static/staticDayTime')
  
  var toStringDate = require('./toStringDate')
  var isValidDate = require('./isValidDate')
  
  /**
    * 返回某个年份的第几周
    *
    * @param {Date} date 日期或数字
    * @return {Number}
    */
  function getYearWeek (date) {
    date = toStringDate(date)
    if (isValidDate(date)) {
      date.setHours(0, 0, 0, 0)
      date.setDate(date.getDate() + 3 - (date.getDay() + 6) % 7)
      var week = new Date(date.getFullYear(), 0, 4)
      return Math.round(((date.getTime() - week.getTime()) / staticDayTime + (week.getDay() + 6) % 7 - 3) / 7) + 1
    }
    return NaN
  }
  
  module.exports = getYearWeek
  