Since moment-timezone was added, there's no need for zone name list

src/components/FieldTimeZoneSelect/FieldTimeZoneSelect.js

@@ -1,20 +1,21 @@
 import React from 'react';
-import { array, string } from 'prop-types';
+import { string } from 'prop-types';
+import { getTimeZoneNames } from '../../util/dates';
 import { FieldSelect } from '../../components';
 
-// You can update timezone keys if needed by running timezone script (aka parse-iana-timezones.js).
-// We have a script that can generate keys from moment-timezone data format
-// https://github.com/moment/moment-timezone/tree/develop/data/unpacked
-// Check the instructions from generated file: iana-2019b-keys.js
-import timezones from './iana-2019b-keys.js';
-
 const FieldTimeZoneSelect = props => {
+
+  // IANA database contains irrelevant time zones too.
+  const relevantZonesPattern = new RegExp(
+    '^(Africa|America|Antarctica|Asia|Atlantic|Australia|Europe|Indian|Pacific)'
+  );
+
   return (
     <FieldSelect {...props}>
       <option disabled value="">
         Pick something...
       </option>
-      {timezones.map(tz => (
+      {getTimeZoneNames(relevantZonesPattern).map(tz => (
         <option key={tz} value={tz}>
           {tz}
         </option>
@@ -28,7 +29,6 @@ FieldTimeZoneSelect.defaultProps = {
   className: null,
   id: null,
   label: null,
-  timezones: timezones,
 };
 
 FieldTimeZoneSelect.propTypes = {
@@ -40,8 +40,6 @@ FieldTimeZoneSelect.propTypes = {
   id: string,
   label: string,
   name: string.isRequired,
-
-  timezones: array,
 };
 
 export default FieldTimeZoneSelect;