Time Zone Converter

Convert times between zones with a focus on UTC. Everything runs in your browser.

Current Time

Zone	Abbr	Time	Date

Convert

Date & Time

From

Result

Use this tool from AI agents

This tool's engine is available to AI agents over MCP as convert_timezone. Add the Clean.tools server, then your agent can call it directly.

Claude Code

claude mcp add --transport http clean-tools https://mcp.clean.tools/mcp

Claude Desktop (mcpServers)

{"mcpServers":{"clean-tools":{"command":"npx","args":["-y","@clean-tools/mcp"]}}}

Cursor

https://mcp.clean.tools/mcp

Or call it over plain HTTP from any script. Same engine, JSON in and JSON out, no key:

curl

curl -s https://api.clean.tools/v1/convert_timezone \
  -H 'content-type: application/json' \
  -d '{"datetime":"2025-07-06T09:30","fromTz":"America/New_York","toTz":"Asia/Tokyo"}'

JavaScript

const res = await fetch('https://api.clean.tools/v1/convert_timezone', {
  method: 'POST',
  headers: { 'content-type': 'application/json' },
  body: JSON.stringify({ datetime: '2025-07-06T09:30', fromTz: 'America/New_York', toTz: 'Asia/Tokyo' })
});
const data = await res.json();

OpenAPI spec npm: @clean-tools/mcp Full developer guide

How it works

This time zone converter uses the browser's built-in Intl.DateTimeFormat API to convert between time zones. The current time display updates every second and shows times across popular developer-friendly zones. All conversions happen locally in your browser. You can also run the same conversion from scripts or AI agents through the Clean.tools timezone API, or install the @clean-tools/mcp package from npm to expose convert_timezone as a local MCP server.

Your data never leaves your device. There are no server requests, no tracking, and no accounts. Works on any modern browser, on both mobile and desktop.

Frequently asked questions

Does it handle daylight saving time?

Yes. Because conversions use named IANA zones such as America/New_York rather than fixed offsets, the correct daylight saving rule is applied for the exact date you enter. A conversion in July and one in January for the same zone can therefore differ by an hour.

Which zone does the date and time field use?

The value you type is read as the wall-clock time in the "From" zone, then converted to the "To" zone. If your input is actually in a different zone, change the "From" selector before reading the result.

Why are the clock and results in 24-hour format?

Times use a 24-hour format to avoid AM/PM ambiguity around midnight and noon. The main clock is labelled UTC explicitly, and the result includes the full date so you can see when a conversion crosses into the next or previous day.

Is my date and time data sent anywhere?

No. Every conversion runs locally using your browser's built-in Intl.DateTimeFormat API. Nothing you enter is uploaded, stored, or tracked.

Can I use this from the command line or an AI agent?

Yes. The same engine is available as a REST endpoint at https://api.clean.tools/v1/convert_timezone, so you can POST a JSON body from curl or any script and get the converted time back as JSON. It is also an MCP server you can add to Claude, Claude Code, or Cursor, which lets an agent call the conversion directly. The @clean-tools/mcp npm package runs the same server locally over stdio if you prefer not to use the hosted endpoint.

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Use Clean.tools from your AI agent

This tool is also convert_timezone on the Clean.tools MCP server — the same engine, callable by your AI agent directly. No key, no signup: requests are processed in memory and request contents are never stored.

Claude Code

claude mcp add --scope user --transport http clean-tools https://mcp.clean.tools/mcp

Any MCP client (streamable HTTP, authless)

https://mcp.clean.tools/mcp

Every tool, the REST API, and setup for Cursor, Claude Desktop, VS Code & more →