ToolFactory

Time Zone Converter

Time Zone Converter: free, instant and private. Offsets are read from your browser’s own timezone database, so daylight-saving changes are handled for the date you entered — not for today.

How the Time Zone Converter works

The Time Zone Converter takes Date & time (local to From zone), From zone, To zone and returns the answer instantly — no button to hunt for, no page reload. Offsets are read from your browser’s own timezone database, so daylight-saving changes are handled for the date you entered — not for today. That matters when scheduling calls across the US and Europe.

Enter your own numbers to replace the example values; the result panel updates as you type. Everything runs in this single page, so nothing you enter leaves your device.

Formula used

target time = source wall-clock time − source UTC offset + target UTC offset

SymbolMeaning
date & timethe clock time in the source zone
from / to zonethe two IANA time zones

Offsets are read from your browser’s own timezone database, so daylight-saving changes are handled for the date you entered — not for today. That matters when scheduling calls across the US and Europe.

Inputs used: Date & time (local to From zone), From zone, To zone.

Worked example

Take the default example — date & time (local to from zone) of 2026-01-01T09:00, from zone set to Asia/Kolkata, to zone set to America/New_York:

Frequently asked questions

What formula does the Time Zone Converter use?
It uses target time = source wall-clock time − source UTC offset + target UTC offset, where date & time is the the clock time in the source zone; from / to zone is the the two IANA time zones.
Is the Time Zone Converter free?
Yes. There is no signup, no usage limit and no watermark — the converter runs entirely in your browser.
How do I read the result?
Offsets are read from your browser’s own timezone database, so daylight-saving changes are handled for the date you entered — not for today. That matters when scheduling calls across the US and Europe.
Does the Time Zone Converter store or send my data?
No. Every calculation happens locally in the page, so the numbers you type are never uploaded or logged.
Does it work on a phone and offline?
Yes — the page is a single lightweight file that adapts to any screen size. Once it has loaded it keeps working without a network connection.