How to get Date object from ISO Date string without dash(-) and colon(:) in Javascript

Question

I was converting ICS to JSON, but it gave me date in the format like "20190103T073640Z", How to I get date object from this string in Javascript?

I know there are lots of answers for "how to convert ISO string to date object", but this string is missing dash and colon.

For e.g When I add dash and colonn, it gives output correctly

new Date("2019-01-03T07:36:40Z");

But how to get a date object in javascript from date string like this without dash and colons "20190103T073640Z"??

Edit for people who think this is duplicate - I have ICalendar file, I am using online converter to convert it to JSON, so the converter I am using giving out the date in that format which is not in the format which I can directly pass to new Date() to get a date object out of it. So is there any method which could parse "20190103T073640Z" string like this.

Thanks.

add dash and colon to the string. if you know this is always in same format. — Kaushik, Dec 26 '18 at 07:14
Use proper date format, as the date string you are using is invalid. Refer this for checking if date is valid: https://stackoverflow.com/questions/1353684/detecting-an-invalid-date-date-instance-in-javascript — Abhilasha, Dec 26 '18 at 07:32
Possible duplicate of [Converting a string to a date in JavaScript](https://stackoverflow.com/questions/5619202/converting-a-string-to-a-date-in-javascript) — Heretic Monkey, Dec 26 '18 at 07:34

score 4 · Accepted Answer · answered Dec 26 '18 at 08:43

What about just extracting each date component, and creating a new Date object using the normal constructors?

function parseIcsDate(icsDate) {
  if (!/^[0-9]{8}T[0-9]{6}Z$/.test(icsDate))
    throw new Error("ICS Date is wrongly formatted: " + icsDate);
  
  var year   = icsDate.substr(0, 4);
  var month  = icsDate.substr(4, 2);
  var day    = icsDate.substr(6, 2);
  
  var hour   = icsDate.substr(9, 2);
  var minute = icsDate.substr(11, 2);
  var second = icsDate.substr(13, 2);
  
  return new Date(Date.UTC(year, month - 1, day, hour, minute, second));
}

var date = parseIcsDate("20190103T073640Z");
console.log(date);

score 0 · Answer 2 · answered Sep 29 '20 at 08:44

If the use of a library is justified (in case of other date operations), Luxon is an excellent choice: https://moment.github.io/luxon/

import { DateTime } from 'luxon';

// Creates a DateTime instance from an ISO 8601-compliant string
const date = DateTime.fromISO('2019-01-03T07:36:40Z');

// Format date to ISO 8601 string
// -> '2019-01-03T08:36:40.000+01:00'
date.toISO();

// Set format to 'basic'
// -> '20190103T083640.000+0100'
date.toISO({format: 'basic'});

// We don't need milliseconds
// -> '20190103T083640+0100'
date.toISO({format: 'basic', suppressMilliseconds: true});

// My system uses a time zone with an offset of +01:00, which is used by Luxon as default.
// So I have to convert the date to UTC (offset +00:00).
// -> '20190103T073640Z'
date.toUTC(0).toISO({format: 'basic', suppressMilliseconds: true});

// As an one-liner
DateTime
    .fromISO('2019-01-03T07:36:40Z')
    .toUTC(0)
    .toISO({ format: 'basic', suppressMilliseconds: true })

None of these examples show how to *parse* the date from the format given in the OP to a `Date` object, which is what the question is. — Heretic Monkey, Nov 16 '21 at 13:29

How to get Date object from ISO Date string without dash(-) and colon(:) in Javascript

2 Answers2