@speechkit/speechkit-audio-player/src/utils/DateUtils.js

A web player component that can play audio from https://speechkit.io

const MONTH_NAMES = [
  "January", "February", "March",
  "April", "May", "June", "July",
  "August", "September", "October",
  "November", "December"
]

const SHORT_MONTH_NAMES = [
  "Jan", "Feb", "Mar",
  "Apr", "May", "Jun", "Jul",
  "Aug", "Sep", "Oct",
  "Nov", "Dec"
]

const addAdditionalZero = val => (
  `0${val}`.slice(-2)
)

export const formatDate = (date, withShortNames = false, lang) => {
  const dateObj = new Date(date)
  const day = dateObj.getDate()
  const monthIndex = dateObj.getMonth()
  const year = dateObj.getFullYear()
  const months = withShortNames ? SHORT_MONTH_NAMES : MONTH_NAMES

  return ['ru', 'de'].includes(lang)
    ? ([day, monthIndex + 1].map(item => addAdditionalZero(item))).concat([year]).join('.')
    : `${months[monthIndex]} ${day}, ${year}`
}


export const addDays = (date, days) => {
  const result = new Date(date)
  result.setDate(result.getDate() + days)
  return result
}