Z

Timezone Converter — Free Online World Clock & Meeting Planner

Convert any date and time between IANA timezones. DST-aware, shareable, runs entirely in your browser.

Free No signup Client-side Privacy friendly Updated

Source

UTC:

Converted

  • No matches.
  • No target timezones. Click Add timezone to start.

How to use

  1. 1 Pick the source timezone, date, and time you want to convert from.
  2. 2 Click "Add timezone" to add target zones — search by city or region name.
  3. 3 Each row shows the equivalent local time, UTC offset, and difference from the source.
  4. 4 Click the copy icon to copy a single row, or "Copy link" to share the whole conversion.

Why use this tool

  • IANA timezone database via your browser — covers all named zones, including DST transitions and historical offsets.
  • Saves your target zone list locally — your meeting roster sticks around between sessions.
  • Shareable URLs encode the source instant and target list — perfect for "what time is this for everyone" messages.
  • Pure client-side — no server roundtrip, no tracking of your schedule.

Frequently asked questions

Does it handle daylight saving time?

Yes. The browser's built-in IANA timezone data drives every conversion, so DST start/end transitions, half-hour offsets (India, Nepal), and 45-minute zones (Nepal, Chatham) are all correct for the specific instant being converted.

What if my chosen time falls inside a DST "spring forward" gap?

That local time technically does not exist. The converter resolves it to the nearest valid UTC instant, so you will see a result — but be aware the wall clock skipped that hour locally.

Can I share a converted time with someone?

Yes — click "Copy link". The URL encodes your source zone, date, time, and target list, so the recipient lands on the same conversion you saw.

Is the timezone list complete?

On modern browsers (Chrome 99+, Firefox 93+, Safari 15.4+) the list uses Intl.supportedValuesOf and includes every IANA zone — typically around 400 entries. Older browsers fall back to a 22-zone shortlist of common ones.

Does this work offline?

Yes after the first load. All conversion runs in your browser using built-in Intl APIs — no API call, no server dependency.

What is Timezone Converter?

A Timezone Converter is a tool that maps a date and time in one IANA timezone (for example, "America/New_York") to its equivalent moment in another (for example, "Asia/Tokyo"). DST-aware converters apply the correct offset for the chosen day, including the spring-forward and fall-back transitions. Multi-city comparison lets meeting planners see one moment across every participant's wall clock.

How Timezone Converter compares to alternatives

Timezone Converter versus typical browser and desktop alternatives — features compared at a glance.
Feature Zerethon Tools Typical online tools Desktop apps
IANA timezone database Yes Sometimes Yes
DST transitions handled Yes Sometimes Yes
Multi-city comparison Yes Rarely Sometimes
Shareable URLs Yes Rarely No
Runs offline Yes (after load) No Yes
Free Yes Yes (with ads) Often free
Summary

Timezone Converter is a free developer utility by Zerethon Tools. Convert any date and time between IANA timezones. DST-aware, shareable, runs entirely in your browser. Runs entirely in the browser — no signup, no upload.

Category
Developer
Pricing
Free
Privacy
Browser-based
Signup
Not required

Privacy

Your data never leaves your browser unless explicitly stated. Timezone Converter runs entirely client-side — no server upload, no logging, no tracking of your input.

Related tools

JSON Formatter

Format, validate, and minify JSON online. Free, no signup — your data never leaves your browser.

Open tool

SQL Formatter

Format SQL queries online — beautify MySQL, PostgreSQL, SQLite, SQL Server, Oracle, and BigQuery.

Open tool

UUID Generator

Generate UUIDs online — v1, v4, v7, and Nil. Bulk generation up to 10,000. Free, no signup.

Open tool

Password Generator

Generate strong, cryptographically random passwords. Configurable length and character sets — runs in your browser.

Open tool

Build, share, and grow on Zerethon Social

Free signup. Earn points, collect achievements, and connect with creators worldwide.

Try Zerethon free