Add city timezone lookup

types/timezone.js

@@ -0,0 +1,31 @@
+const { ArgumentType } = require('discord.js-commando');
+const cityTimezones = require('city-timezones');
+const moment = require('moment-timezone');
+
+module.exports = class TimezoneType extends ArgumentType {
+	constructor(client) {
+		super(client, 'timezone');
+	}
+
+	validate(value) {
+		value = value.replaceAll(' ', '_').toLowerCase();
+		const directZone = moment.tz.zone(value);
+		if (directZone) return true;
+		const cityZone = cityTimezones.lookupViaCity(value);
+		if (cityZone.length) return true;
+		const provZone = cityTimezones.findFromCityStateProvince(value);
+		if (provZone.length) return true;
+		return false;
+	}
+
+	parse(value) {
+		value = value.replaceAll(' ', '_').toLowerCase();
+		const directZone = moment.tz.zone(value);
+		if (directZone) return directZone.name;
+		const cityZone = cityTimezones.lookupViaCity(value);
+		if (cityZone.length) return cityZone[0].timezone;
+		const provZone = cityTimezones.findFromCityStateProvince(value);
+		if (provZone.length) return provZone[0].timezone;
+		return null;
+	}
+};