How do I format a date as ISO 8601 in moment.js?

Question

This docs mention moment.ISO_8601 as a formatting option (from 2.7.0 - http://momentjs.com/docs/#/parsing/special-formats/), but neither of these work (even 2.7.0):

var date = moment();
date.format(moment.ISO_8601); // error
moment.format(date, moment.ISO_8601); // error

(http://jsfiddle.net/b3d6uy05/1/)

How can I get an ISO 8601 from moment.js?

Solution 1

moment().toISOString(); // or format() - see below

http://momentjs.com/docs/#/displaying/as-iso-string/

Update Based on the answer: by @sennet and the comment by @dvlsg (see Fiddle) it should be noted that there is a difference between format and toISOString. Both are correct but the underlying process differs. toISOString converts to a Date object, sets to UTC then uses the native Date prototype function to output ISO8601 in UTC with milliseconds (YYYY-MM-DD[T]HH:mm:ss.SSS[Z]). On the other hand, format uses the default format (YYYY-MM-DDTHH:mm:ssZ) without milliseconds and maintains the timezone offset.

I've opened an issue as I think it can lead to unexpected results.

Solution 2

Use format with no parameters:

var date = moment();
date.format(); // "2014-09-08T08:02:17-05:00"

(http://jsfiddle.net/8gvhL1dz/)

Solution 3

Also possible with vanilla JS

new Date().toISOString() // "2017-08-26T16:31:02.349Z"

Solution 4

When you use Mongoose to store dates into MongoDB you need to use toISOString() because all dates are stored as ISOdates with miliseconds.

moment.format() 

2018-04-17T20:00:00Z

moment.toISOString() -> USE THIS TO STORE IN MONGOOSE

2018-04-17T20:00:00.000Z

Solution 5

var date = moment(new Date(), moment.ISO_8601);
console.log(date);

View more solutions

Comments

[joews]

What version of moment are you using? The docs say that constant was added in 2.7.0.

[sennett]

@joews 2.7.0. Clarified in question. See my answer I figured it out. Docs not hugely clear though.

[joews]

Yeah, they only mention special formats in the context of parsing. Odd.

[Saahithyan Vigneswaran]

u can try moment().toISOString()

[dvlsg]

Just as a side note, these two answers are not the same, even though they both fulfill ISO format requirements. date.toISOString() will keep the milliseconds and use utc, date.format() will drop the milliseconds and use your local timezone (or at least, that's the behavior I am currently getting in chrome -- jsfiddle.net/8gvhL1dz/22 )

[Greivin López]

I agree with you @Yashua. I think the use of "format()" should be avoided because is not intuitive. Also I don't think a function that just wraps the native "toISOString()" should exist at all. That being said, perhaps giving a new function like: "toISO8601()" with the option to keep the timezone and a proper documentation will be better.

[StinkyCat]

If you want the utc time, but formatted your own way, instead of ISO8601, you can do the following: moment().utc().format("OUTPUT_FORMAT")

[Matt Sgarlata]

Using .format() with an Arabic locale leads to Arabic symbols rather than English ones, which is probably undesirable.

[Brice]

Useful whn formating a date in kibana but you don't have access to JS.

[JoeTidee]

Only if you want it in UTC, without maintaining the timezone.

[JoeTidee]

toISOString does not output in your local timezone - it is always in (zero offset) UTC.

[Benny Neugebauer]

If you want to maintain the local timezone, use moment().toISOString(true);.

[borchvm]

While this code may provide a solution to the question, it's better to add context as to why/how it works. This can help future users learn, and apply that knowledge to their own code. You are also likely to have positive feedback from users in the form of upvotes, when the code is explained.

[Stephan Hogenboom]

Can you elaborate your answer a bit?