JSFiddle - React, Tailwind, and code Playground

JavaScript

function log(msg) {
    $('body').append('<p>' + msg + '</p>');
}

log(JSON.stringify([
    new Date()
]));
   
 //log((new Date()).toJSON());
log(new Date().format('YYYY-MM-DDTHH:mm:ss').toString());
//log((new Date()).valueOf());

log( new Date().format('YYYY-MM-DD[T]HH:mm:ss.SSS'));