getMonthNameAbbr (month, monthsAbbr) {
    if (!monthsAbbr) {
      throw Error('missing 2nd paramter Months array')
    }
    if (typeof month === 'object') {
      return monthsAbbr[this.getMonth(month)]
    }
    if (typeof month === 'number') {
      return monthsAbbr[month]
    }
    throw TypeError('Invalid type')
  }
Return an abbreviated version of the month
@param {Number|Date}
@return {String}