🌍 utc-to-local-timezone

A lightweight, zero-dependency JavaScript package to convert a UTC date string to a local timezone format with customizable date/time patterns. Whether you need to display dates in a specific timezone, support multilingual locales like Hindi with native numerals and AM/PM translations, or format time in 12h/24h — this package’s got you covered!

✨ Features

🔁 Convert UTC time to local time based on a specified timezone
🕒 Customizable date and time formats (12h/24h, slashes, or text)
🌐 Wide range of locales supported — including hi-IN (Hindi)
🔡 Hindi output with native digits like ११ अगस्त, २०२५, ५:३० अपराह्न
📦 Both CommonJS (require) and ES Module (import) compatible
🪶 Clean, lightweight, and no external dependencies

📦 Installation

npm install utc-to-local-timezone

📥 Import Instructions

CommonJS (Node.js)

const utcToLocalTimezone = require('utc-to-local-timezone');

ES Module

import utcToLocalTimezone from 'utc-to-local-timezone';

✅ Both formats are fully supported.

📑 Usage

Function: `utcToLocalTimezone`

Converts a UTC date string to local time according to your locale, timezone, and preferred pattern.

Parameters

Parameter	Type	Description	Default
`utcDateString`	`string`	The UTC date string to convert (optional — uses current UTC time if omitted)	`new Date().toISOString()`
`optionsData`	`object`	Options to customize the output format	`{}`

`optionsData` keys:

locale (string) — Locale to use (default: "en-US")
timezone (string) — Timezone to convert into (default: "Asia/Kolkata")
patternType (string) — Date-Time pattern format (default: "datetime-12h-text")

🔧 Example Usage

1️⃣ Basic Usage (Current Time, Default Locale & Timezone)

console.log(utcToLocalTimezone());
// Example Output (Asia/Kolkata): "May 11, 2025, 5:30 PM"

2️⃣ Specific UTC Date, Custom Format & Locale

const utcDate = "2025-05-11T12:00:00Z";
const options = {
  locale: "hi-IN",
  timezone: "Asia/Kolkata",
  patternType: "datetime-12h-text"
};

console.log(utcToLocalTimezone(utcDate, options));
// Output: "११ मई, २०२५, ५:३० अपराह्न"

3️⃣ 24-hour Format Example

console.log(utcToLocalTimezone("2025-05-11T12:00:00Z", {
  locale: "en-US",
  timezone: "Asia/Kolkata",
  patternType: "datetime-24h-text"
}));
// Output: "May 11, 2025, 17:30"

📊 Example Outputs

Locale	Pattern	Output
en-US	datetime-12h-text	August 11, 2025, 5:30 PM
en-US	datetime-24h-text	August 11, 2025, 17:30
hi-IN	datetime-12h-text	११ अगस्त, २०२५, ५:३० अपराह्न

Available Pattern Types

Pattern Type	Output
date-slash	11/05/2025
date-text	August 11, 2025
datetime-12h-slash	11/05/2025, 5:30 PM
datetime-12h-text	August 11, 2025, 5:30 PM
datetime-24h-slash	11/05/2025, 17:30
datetime-24h-text	August 11, 2025, 17:30

Locales 🌍

Hindi

hi-IN (Hindi, India)

English

en-US (English, United States)
en-GB (English, United Kingdom)
en-AU (English, Australia)
en-CA (English, Canada)
en-IN (English, India)
en-NZ (English, New Zealand)

Spanish

es-ES (Spanish, Spain)
es-MX (Spanish, Mexico)
es-AR (Spanish, Argentina)
es-CO (Spanish, Colombia)
es-CL (Spanish, Chile)

French

fr-FR (French, France)
fr-CA (French, Canada)
fr-BE (French, Belgium)
fr-CH (French, Switzerland)

German

de-DE (German, Germany)
de-AT (German, Austria)
de-CH (German, Switzerland)
de-LI (German, Liechtenstein)

Italian

it-IT (Italian, Italy)
it-CH (Italian, Switzerland)

Portuguese

pt-PT (Portuguese, Portugal)
pt-BR (Portuguese, Brazil)

Arabic:

ar-SA (Arabic, Saudi Arabia)
ar-EG (Arabic, Egypt)
ar-AE (Arabic, UAE)
ar-IQ (Arabic, Iraq)

Chinese

zh-CN (Chinese, Simplified, China)
zh-TW (Chinese, Traditional, Taiwan)
zh-HK (Chinese, Traditional, Hong Kong)

Japanese

ja-JP (Japanese, Japan)

Korean

ko-KR (Korean, South Korea)

Russian

ru-RU (Russian, Russia)
ru-UA (Russian, Ukraine)

Other

pl-PL (Polish, Poland)
nl-NL (Dutch, Netherlands)
sv-SE (Swedish, Sweden)
tr-TR (Turkish, Turkey)

Timezones (IANA Timezone Database) 🌍

Asia

Asia/Kolkata (India Standard Time, India)
Asia/Tokyo (Japan Standard Time, Japan)
Asia/Shanghai (China Standard Time, China)
Asia/Dubai (Gulf Standard Time, UAE)
Asia/Singapore (Singapore Time, Singapore)
Asia/Seoul (Korea Standard Time, South Korea)

Africa

Africa/Abidjan (Ivory Coast)
Africa/Cairo (Egypt)
Africa/Johannesburg (South Africa)
Africa/Nairobi (Kenya)
Africa/Lagos (Nigeria)

America

America/New_York (Eastern Standard Time, USA)
America/Chicago (Central Standard Time, USA)
America/Los_Angeles (Pacific Standard Time, USA)
America/Argentina/Buenos_Aires (Argentina)
America/Sao_Paulo (Brazil)
America/Toronto (Canada)

Australia

Australia/Sydney (Australian Eastern Standard Time)
Australia/Melbourne (Australian Eastern Standard Time)
Australia/Perth (Australian Western Standard Time)

Europe

Europe/London (Greenwich Mean Time, UK)
Europe/Paris (Central European Time, France)
Europe/Berlin (Central European Time, Germany)
Europe/Madrid (Central European Time, Spain)
Europe/Amsterdam (Central European Time, Netherlands)
Europe/Moscow (Moscow Standard Time, Russia)

Pacific

Pacific/Auckland (New Zealand Standard Time, New Zealand)
Pacific/Fiji (Fiji Standard Time, Fiji)
Pacific/Honolulu (Hawaii-Aleutian Standard Time, USA)
Pacific/Tongatapu (Tonga Time, Tonga)

🤝 Contributing

Found a bug, or want to add a new pattern?
Feel free to open an issue or PR — contributions welcome! 🚀

📄 License

MIT License — see the LICENSE file for details.

Package detail