How to convert Moment.js date to users local timezone?

I use the Moment.js and Moment-Timezone frameworks, and have a Moment.js date object which is explicitly in UTC timezone. How can I convert that to the current timezone of the browser?

var testDateUtc = moment.tz("2015-01-30 10:00:00", "UTC");
var localDate = ???

So it would be fine if I could find out the users local time zone; or alternatively I'd like to convert the date object into another data object which just uses the "local timezone", no matter what that actually is.

You do not need to use moment-timezone for this. The main moment.js library has full functionality for working with UTC and the local time zone.

var testDateUtc = moment.utc("2015-01-30 10:00:00");
var localDate = moment(testDateUtc).local();

From there you can use any of the functions you might expect:

var s = localDate.format("YYYY-MM-DD HH:mm:ss");
var d = localDate.toDate();
// etc...

Note that by passing testDateUtc, which is a moment object, back into the moment() constructor, it creates a clone. Otherwise, when you called .local(), it would also change the testDateUtc value, instead of just the localDate value. Moments are mutable.

Also note that if your original input contains a time zone offset such as +00:00 or Z, then you can just parse it directly with moment. You don't need to use .utc or .local. For example:

var localDate = moment("2015-01-30T10:00:00Z");

var dateFormat = 'YYYY-DD-MM HH:mm:ss';
var testDateUtc = moment.utc('2015-01-30 10:00:00');
var localDate = testDateUtc.local();
console.log(localDate.format(dateFormat)); // 2015-30-01 02:00:00

1. Define your date format.
2. Create a moment object and set the UTC flag to true on the object.
3. Create a localized moment object converted from the original moment object.
4. Return a formatted string from the localized moment object.

See: http://momentjs.com/docs/#/manipulating/local/

Here's what I did:

var timestamp = moment.unix({{ time }});
var utcOffset = moment().utcOffset();
var local_time = timestamp.add(utcOffset, "minutes");
var dateString = local_time.fromNow();

Where {{ time }} is the utc timestamp.

Use utcOffset function.

var testDateUtc = moment.utc("2015-01-30 10:00:00");
var localDate = moment(testDateUtc).utcOffset(10 * 60); //set timezone offset in minutes
console.log(localDate.format()); //2015-01-30T20:00:00+10:00

class Time extends React.Component {
  constructor(props) {
    super(props)
    this.state = {
      parentTime: '',
      localTime: '',
      parentTz: ''
    }
  }

  componentDidMount() {
    const inputTz = "America/Toronto"
    const originTime = "2013-11-18 11:55"
    const time = moment.tz(originTime, inputTz)
    const localtz = moment.tz.guess()
    const date = time.clone().tz(localtz)
    const formatDate = moment(date).format('MMMM Do YYYY, h:mm:ss A z')
     console.log(formatDate, localtz)
    this.setState({parentTime: originTime, localTime: formatDate, parentTz: inputTz })
  }


  render() {
  const {parentTime, parentTz, localTime} = this.state
    return (
      <div>
      <p>{parentTime}<br/> in {parentTz}<br/> to {localTime}</p>
      </div>
    )
  }
}


ReactDOM.render(
  <Time />,
  document.getElementById('time')
);

<script src="https://momentjs.com/downloads/moment.js"></script>
<script src="https://momentjs.com/downloads/moment-timezone.js"></script>
<script src="https://momentjs.com/downloads/moment-timezone-with-data-1970-2030.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.3.0/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/15.3.0/react-dom.min.js"></script>
<div id="time"></div>

the best way to get a user's time zone is using moment-timezone

import moment from 'moment-timezone'

// using utc time here
const time = moment.tz("2021-04-14T02:08:10.370Z")
const localtz = moment.tz.guess()
const date = time.clone().tz(localtz)
const formatDate = moment(date).format('MMMM Do YYYY, h:mm:ss A z')
console.log(formatDate)

this way you will be able to convert your time into a local timezone specific time