The toISOString() method of Date instances returns a string representing this date in the date time string format, a simplified format based on ISO 8601, which is always 24 or 27 characters long (YYYY-MM-DDTHH:mm:ss.sssZ or ±YYYYYY-MM-DDTHH:mm:ss.sssZ, respectively). The timezone is always UTC, as denoted by the suffix Z.
const event = new Date("05 October 2011 14:48 UTC");
console.log(event.toString());
// Expected output: "Wed Oct 05 2011 16:48:00 GMT+0200 (CEST)"
// Note: your timezone may vary
console.log(event.toISOString());
// Expected output: "2011-10-05T14:48:00.000Z"toISOString()None.
A string representing the given date in the date time string format according to universal time. It's the same format as the one required to be recognized by Date.parse().
RangeErrorThrown if the date is invalid or if it corresponds to a year that cannot be represented in the date string format.
const d = new Date(0);
console.log(d.toISOString()); // "1970-01-01T00:00:00.000Z"