Convert Date/TimeStamp to ISO

toISO.js

function toISO(date) {
  // If the date is already an ISO string, return it as-is
  if (typeof date === 'string' && /^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}\.\d{3}Z$/.test(date)) {
    return date;
  }

  // If the date is a number, assume it's a timestamp and convert it to a Date object
  if (typeof date === 'number') {
    date = new Date(date);
  }

  // If the date is still not a Date object, try to parse it as a string
  if (!(date instanceof Date)) {
    date = new Date(date);
  }

  // If the date is still invalid, return an empty string
  if (isNaN(date.getTime())) {
    return '';
  }

  // Return the date as an ISO string
  return date.toISOString();
}

const date = '2022-12-28';
const isoDate = toISO(date);
console.log(isoDate); // Output: "2022-12-28T00:00:00.000Z"

const timestamp = 1609459200000;
const isoTimestamp = toISO(timestamp);
console.log(isoTimestamp); // Output: "2022-12-28T00:00:00.000Z"