Pure JavaScript JST Time

jstTime.js

// どの環境で実行しても、JST時刻を取得する

const timeZoneOffset = 9 // JST

const getJstDate = () => {
  const time = Date.now() // UTC millisecond
  const date = new Date(time) // local date
  const utcHours = date.getUTCHours() // UTC Hour
  date.setHours(utcHours + timeZoneOffset) // UTC Hour + TimeZone Offset
  return {
    time,
    tzYear: date.getFullYear(),
    tzMonth: date.getMonth() + 1,
    tzDate: date.getDate(),
    tzDay: date.getDay()
  }
}