code: function getMonthWeek (date) {
    var monthFirst, monthFirstWeek
    var currentDate = toStringDate(date)
    if (baseExports.isDate(currentDate)) {
      monthFirst = getWhatMonth(currentDate, 0, STRING_FIRST)
      monthFirstWeek = getWhatWeek(monthFirst, 0, 1)
      if (monthFirstWeek < monthFirst) {
        monthFirstWeek = getWhatWeek(monthFirst, 1, 1)
      }
      if (currentDate >= monthFirstWeek) {
        return Math.floor((getYMDTime(currentDate) - getYMDTime(monthFirstWeek)) / WEEK_TIME) + 1
      }
      return getMonthWeek(getWhatWeek(currentDate, 0, 1))
    }
    return currentDate
  }
docs: 返回某个月的第几周
  
  @param {Date} date 日期或数字
  @return {Number}