Convert user define time to UTC using moment

Question

We have application where we ask user to define time when they want to publish some content. In our application, user will select that content should publish X(0-5) day before target date and y time (0-23).

So if user create a content with publish date = "09/21/2021" and publish time as 3 it means this content needs to publish at 3 AM on 09/21/2021.

In our Mongo DB we need to store the calculated date as "2021-09-21T07:00:00" So it can be pulled by our Cron Job.

We tried will following without any success

 var promotedDate = "2021-08-19 04:00:00" var fmt = "YYYY-MM-DD hh:mm:ss"; var m = moment.utc(promotedDate, fmt); console.log('promoted date ', tempDate) console.log(m.local().format(fmt)); console.log(m.utc().format(fmt));

But it gives 2021-08-19 12:00:00

Any help?

Answer 1

You can use moment.toISOString() . That will give you UTC regardless of the timezone of the moment in question thus: 2013-02-04T22:44:30.652Z .

Since that comes with milliseconds and a Z for Zulu time, we need to strip off the last 5 characters with string.slice() :

const promotedDate = "2021-08-19 04:00:00";
const m            = moment.utc(promotedDate, "YYYY-MM-DD hh:mm:ss");
const iso8601      = m.toISOString()
                      .slice(0,-5); // removes milliseconds and `Z` for Zulu

console.log( `promoted: ${promotedDate}` );
console.log( `iso8601:  ${iso8601} );