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bypabloc_
Asked: 2020-12-08 18:32:18 +0800 CST 2020-12-08 18:32:18 +0800 CST

Pass date GTM 0 to local

  • 772

I want to pass a date that is in GTM0 to my local time, according to momentjs it 's like this , but I can't convert the date to my local time.

moment.locale('es');

let fecha = '2018-12-07 22:56:48';

let fecha_origin = moment(fecha).format('DD [de] MMM [del] YYYY [a las] hh:mm:ss A');
console.log('Fecha original: ', fecha_origin);

let fecha_local = moment(fecha).utc().format('DD [de] MMM [del] YYYY [a las] hh:mm:ss A');
console.log('Conversión: ', fecha_local);
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.22.2/moment-with-locales.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment-timezone/0.5.23/moment-timezone-with-data.min.js"></script>

Update 1:

My local time is supposed to be -5, instead it's +5 when I do the conversion.

result

javascript

4 Answers

  1. The problem is that you are trying to parse a date that has no UTC information anywhere. That can be known immediately if we break down the date you use as input

    let fecha = '2018-12-07 22:56:48'

    The date would be 2018-12-07and the time 22:56:48separated by space

    The UTC information should go at the end as +hh:mmor -hh:mm, if it is in UTC it should be+00:00

    If the time snippet is included, an offset from UTC can also be included as +-HH:mm, +-HHmm, +-HH or Z

    Changing the date input works perfectly. I used Tas a spacer.

    moment.locale('es');

let fecha = '2018-12-07T22:56:48+00:00';

let fecha_origin = moment(fecha).local().format('DD [de] MMM [del] YYYY [a las] hh:mm:ss A');
console.log('Fecha en local: ', fecha_origin);

let fecha_local = moment(fecha).utc().format('DD [de] MMM [del] YYYY [a las] hh:mm:ss A');
console.log('En utc: ', fecha_local);
console.log('Offset', moment().utcOffset() / 60);
    <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.22.2/moment-with-locales.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment-timezone/0.5.23/moment-timezone-with-data.min.js"></script>

    The other way is that instead of moment(fecha).utc()using moment.utc(fecha)it directly since, as you say, it comes in utc from the server.

    moment.locale('es');

let fecha = '2018-12-07 22:56:48';

let fecha_origin = moment.utc(fecha).local().format('DD [de] MMM [del] YYYY [a las] hh:mm:ss A');
console.log('Fecha en local: ', fecha_origin);

let fecha_local = moment.utc(fecha).format('DD [de] MMM [del] YYYY [a las] hh:mm:ss A');
console.log('En utc: ', fecha_local);
console.log('Offset', moment().utcOffset() / 60);
    <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.22.2/moment-with-locales.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment-timezone/0.5.23/moment-timezone-with-data.min.js"></script>

    The difference is in how it is processed . Remember that your initial date has no offset information so if you use moment(fecha).utc()what it will do is interpret it as local time and then convert it to utc by adding or subtracting hours (hence your problem). If you specify it moment.utc(fecha)then it will interpret it as utc directly, that is+00:00

    • 7
  2. Best Answer

    Let's first understand how dates work with moment.js, by looking at examples, but first:

    moment.locale('es');

    This only affects the language, that is, whether to write Dec(ember) or dic(ember), not the time. Therefore we can rule it out as a cause of problems

    let fecha = '2018-12-07 22:56:48';

    You define a moment in a standard format . But what time is it? Let's do some tests to check it out. I am in GMT+1 (Spain):

    let momento = moment();

console.log('sin formato', momento);
//sin formato "2018-12-14T16:49:56.834Z"

console.log('con formato', momento.format('DD [de] MMM [del] YYYY [a las] hh:mm:ss A'));
//con formato 14 de Dec del 2018 a las 05:49:56 PM

    We already see a difference: without formatting, Zulu time is used (hence the final Z), while when formatting, the Local Zone of my machine's operating system is used.

    Zulu time is UTC time , which coincides with GMT+0

    Now let's try to parse a date:

    let fecha  = '2018-12-07 22:56:48'; //sin zona definida
let fecha2 = '2018-12-07 22:56:48+01:00'; //con mi zona
let fecha3 = '2018-12-07 22:56:48Z'; //con zona 00
let momento = moment(fecha);
let momento2 = moment(fecha2);
let momento3 = moment(fecha3);

//al no definir la zona se muestra siempre hora Zulu:

 
//asume mi zona del SO, le resta 1 hora
//En tu caso esta ejecución debería sumar 5 horas
console.log('sin formato', momento);

//especificamos que la zona es +1, le resta 1 hora para mostar la hora Zulú
console.log('sin formato', momento2);

//Explícitamente es Zulú, no tiene que sumar o restar
console.log('sin formato', momento3);

const formato='DD [de] MMM [del] YYYY [a las] hh:mm:ss A';

//Al usar un formato, se usa la hora local
console.log('con formato', momento.format(formato));
console.log('con formato', momento2.format(formato));
console.log('con formato', momento3.format(formato)); //Se le suma una hora a la Zulu

//formato, pero pidiendo utc:
console.log('con formato en UTC (+00)', momento.utc().format(formato));
    <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.22.2/moment-with-locales.min.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/moment-timezone/0.5.23/moment-timezone-with-data.min.js"></script>

    So we see that the problem is that when you write:

    let fecha_local = moment(fecha).utc().format('DD [de] MMM [del] YYYY [a las] hh:mm:ss A');
console.log('Conversión: ', fecha_local);

    You are making a misconception:

     moment(fecha) //parseas una hora local (-5)
  .utc() //pides que te la traslade a UTC (le suma 5 horas)
  .format('DD [de] MMM [del] YYYY [a las] hh:mm:ss A'); // y la muestras
    • 4

  3. utc() should go on the original date and on the local date apply local(). With the following example ami it works perfectly for me. The code should look like this:

    moment.locale('es');

let fecha = '2018-12-07 22:56:48';

let fecha_origin = moment(fecha).utc().format('DD [de] MMM [del] YYYY [a las] hh:mm:ss A');
console.log('Fecha original: ', fecha_origin);

let fecha_local = moment(fecha).format('DD [de] MMM [del] YYYY [a las] hh:mm:ss A');
console.log('Conversión: ', fecha_local);
    <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.22.2/moment-with-locales.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment-timezone/0.5.23/moment-timezone-with-data.min.js"></script>

    • 1

  4. This way I get the date with the time zone you need: The image shows the capture in the console. (Do the test locally)

    enter image description here

    <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.22.2/moment-with-locales.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment-timezone/0.5.23/moment-timezone-with-data.min.js"></script>

<script>
	moment.locale('es');

	let fecha = '2018-12-07 22:56:48';

	let fecha_local = moment.utc(fecha).toDate();
	console.log('Conversión: ', fecha_local);
</script>

    • 1