Date as YYYY-MM-DD HH:MM:SS.sss as local time (ISO 8601)

prettyDate.js

function prettyDate(date) {
  const dateStr = [`${date.getFullYear()}`, `${date.getMonth() + 1}`, `${date.getDate()}`]
    .map((part) => part.padStart(2, '0'))
    .join('-');
  const timeStr = [`${date.getHours()}`, `${date.getMinutes()}`, `${date.getSeconds()}`]
    .map((part) => part.padStart(2, '0'))
    .join(':');
  const fractionStr = `${date.getMilliseconds()}`.padStart(3, '0');

  return `${dateStr} ${timeStr}.${fractionStr}`;
}

// Example usage of printing the current date/time:
console.log(prettyDate(new Date()));

// Try fiddle with date yourself (printed differently depending on your time zone):
const parsedDate = Date.parse("2023-12-31T23:01:02.003Z");
console.log(prettyDate(new Date(parsedDate)));