以前のリビジョンの文書です
let nowTime = new Date();
let time = nowTime.getFullYear();
console.log(time)
time += "0" + (nowTime.getMonth() + 1)
console.log(time)
time += "0" + (nowTime.getDate())
console.log(time)
time += "0" + (nowTime.getHours())
console.log(time)
time += "0" + (nowTime.getMinutes())
console.log(time)
time += "0" + (nowTime.getSeconds())
console.log(time)