SOURCE

function convertTimestamp(timestamp) {
    var date = new Date(timestamp);
    var year = date.getFullYear();
    var month = date.getMonth() + 1;
    var day = date.getDate();
    var hours = date.getHours();
    var minutes = "0" + date.getMinutes();
    var seconds = "0" + date.getSeconds();
    return year + '-' + month + '-' + day + ' ' + hours + ':' + minutes.substr(-2) + ':' + seconds.substr(-2);
}
var timestamp = Date.now();
console.log(timestamp-'1682213807495');