[JavaScript]時間（タイムスタンプ）を四捨五入する

今回の目的：10分単位で四捨五入したい

日本語でググっても出てこないので英語「js timestamp round」でググった

四捨五入したい時間の分をgetMinutes()で取り出す（toString

も忘れずに）＋下記コードで動作確認できた

Round a Date() to the nearest 5 minutes in javascript

https://stackoverflow.com/questions/10789384/round-a-date-to-the-nearest-5-minutes-in-javascript

const roundDownTo = roundTo => x => Math.floor(x / roundTo) * roundTo;
const roundUpTo = roundTo => x => Math.ceil(x / roundTo) * roundTo;
const roundDownTo5Minutes = roundDownTo(1000*60*5);
const roundUpTo5Minutes = roundUpTo(1000*60*5);

const now = new Date();
const msdown = roundDownTo5Minutes(now)
const msup = roundUpTo5Minutes(now)
console.log(now);
console.log(new Date(msdown));
console.log(new Date(msup));