How to get the list of all available timezone using moment-timezone

Based on @Shrabanee answer and according to @Tenz comment - this is my solution with es6 Template literals and with sorting the list by the GMT + number instead of the timezone name:

    timeZones = momentTimezone.tz.names();
    let offsetTmz=[];

    for(let i in timeZones)
    {
        offsetTmz.push(`(GMT${moment.tz(timeZones[i]).format('Z')}) ${timeZones[i]}`);
    }

    this.timeZoneNames = offsetTmz.sort();

Based on the answer by Erez Liberman and the answer by Matt Johnson about trimming the list I would like to add mine as a full Typescript class, that sorts timezones with negative offset in reverse order

import * as moment from 'moment-timezone';

export class TimezoneData {
    tzName: string;
    tzPresentationName: string;
}

export class TimezoneUtils {

    public static getTimezonesNames(): TimezoneData[] {
        const arr: TimezoneData[] = [];
        const names = moment.tz.names();
        for (const name of names) {
            if ((name.indexOf('/') < 0 && name !== 'UTC') || name.startsWith('Etc/')) {
                continue;
            }
            const data = new TimezoneData();
            data.tzName = name;
            data.tzPresentationName = moment.tz(name).format('Z');
            arr.push(data);
        }
        arr.sort((a, b) => {
            if (a.tzPresentationName === b.tzPresentationName) {
                if (a.tzName === 'UTC') {
                    return -1;
                }
                return a.tzName === b.tzName ? 0 : (a.tzName > b.tzName ? 1 : -1);
            }
            const afc = a.tzPresentationName.charAt(0);
            const bfc = b.tzPresentationName.charAt(0);
            if (afc === '-') {
                if (bfc === '+') {
                    return -1;
                }
                return a.tzPresentationName > b.tzPresentationName ? -1 : 1;
            }
            if (bfc === '-') {
                return 1;
            }
            return a.tzPresentationName > b.tzPresentationName ? 1 : -1;
        });
        arr.forEach(a => a.tzPresentationName = `${a.tzName} (GMT ${a.tzPresentationName})`);
        return arr;
    }
}

There is no straight way of getting in the format you want, directly from moment-timezone.

Try like below.

var moment = require('moment-timezone');
var timeZones = moment.tz.names();
var offsetTmz=[];

for(var i in timeZones)
{
    offsetTmz.push(" (GMT"+moment.tz(timeZones[i]).format('Z')+") " + timeZones[i]);
}

Now, offsetTmz is an array of strings in the format you want.

This is how I am using it.

Hope this will help you.