Basic date object Date object converted into the string doesn't look good. new Date().toString() Sun Oct 27 2024 09:32:40 GMT+0200 (Itä-Euroopan normaaliaika) Function // functions/ddmmyyyyHHMMSS.js export const ddmmyyyyHHMMSS = (date = new Date(), utc = false) => { if (isNaN(Date.parse(date))) return 'can not parse date' const addZeroToNum = (num) => num.toString().length === 1 ? '0' + num : num const d = new Date(date) const yyyy = utc ? d.getUTCFullYear() : d.getFullYear() const mm = addZeroToNum(utc ? d.getUTCMonth() + 1 : d.getMonth() + 1) const dd = addZeroToNum(utc ? d.getUTCDate() : d.getDate()) const HH = addZeroToNum(utc ? d.getUTCHours() : d.getHours()) const MM = addZeroToNum(utc ? d.getUTCMinutes() : d.getMinutes()) const SS = addZeroToNum(utc ? d.getUTCSeconds() : d.getSeconds()) return `${dd}.${mm}.${yyyy} ${HH}:${MM}:${SS}` } Output new Date().toString() Sun Oct 27 2024 09:32:40 GMT+0200 (Itä-Euroopan normaaliaika) new Date().toISOString() 2024-10-27T07:32:40.179Z ddmmyyyyHHMMSS(new Date()) 27.10.2024 09:32:40 ddmmyyyyHHMMSS(new Date(), true) 27.10.2024 07:32:40 ddmmyyyyHHMMSS("1999-12-31T15:16:17.340Z") 31.12.1999 17:16:17 ddmmyyyyHHMMSS("1999-12-31T15:16:17.340Z", true) 31.12.1999 15:16:17