Time Zone Converter
Convert times across multiple time zones
Time Zone Converter tool
Time Zone Converter: key facts
- What it does
- Convert times across multiple time zones
- Category
- Converters
- Cost
- Free, with no account, sign-up, or install.
- Your data
- Runs entirely in your browser — the files and text you enter are never uploaded to a server.
- Last reviewed
- . Report an incorrect result.
What the Time Zone Converter does
Scheduling across time zones without getting it wrong requires knowing both the current offset and whether each city is observing daylight saving time right now. A fixed UTC offset is not enough — New York shifts from UTC−5 to UTC−4 in March, and Sydney does the opposite in April. This converter uses your browser's built-in time-zone database (via the Intl.DateTimeFormat API), so the offsets it shows are always correct for the specific date you pick.
Remote engineering teams use it to find a stand-up time that works from San Francisco to Berlin to Singapore. Event organizers post a livestream time and then verify it in half a dozen attendee cities. Travelers confirm what time their connecting flight boards in local time. Freelancers working with international clients know at a glance whether their counterpart is reachable or asleep. You can add up to eight comparison time zones simultaneously and switch between 12-hour and 24-hour display to match what the other person expects to see.
Using the Time Zone Converter, step by step
- Set the base date and time using the date/time picker — it defaults to right now.
- Choose the base time zone (the one your time is already in) from the dropdown.
- The preset comparison zones appear below. Click Add Zone to add more, or the × button on any card to remove one.
- Toggle 12hr / 24hr to match your preference. Each card shows the local time, date, and UTC offset for that zone.
Converting an instant between zones
A moment in time is expressed in one zone and re-expressed in another, using the browser's internationalisation data. The offset applied is the one in force in that zone on that date, so a conversion in January and the same conversion in July can differ by an hour where daylight saving applies.
That date-dependence is the reason zones must be named rather than given as a fixed offset. A stored offset is correct for part of the year and wrong for the rest; a named zone carries the rules that determine which applies.
The difference between the two zones is reported alongside the converted time, which is the figure you want when arranging something recurring.
- New York to London is normally five hours forward, so 09:00 becomes 14:00.
- In the weeks when the two regions change clocks on different dates, the gap is four hours instead.
- India sits at UTC+5:30 and Nepal at UTC+5:45 — offsets that are not whole hours.
What makes this one worth using
- Uses the browser's native Intl.DateTimeFormat time-zone database — daylight saving transitions are handled automatically, with no manual offset table to maintain.
- Supports up to eight comparison zones simultaneously, so a single view covers an entire distributed team.
- A curated list of nineteen commonly needed IANA zones (from UTC to Pacific/Auckland) covers the major world cities without overwhelming you with hundreds of choices.
- Works entirely client-side — no API call is needed, so it works offline once the page has loaded.
The assumptions that fail
Time zones defeat intuition comprehensively. Not every offset is a whole number of hours. Not every country observes daylight saving, and those that do change on different dates — the European Union and the United States are misaligned for several weeks twice a year, which is when recurring transatlantic meetings quietly shift. Southern hemisphere transitions run opposite to northern ones. Some zones have changed by legislation at short notice.
Two habits avoid most of the resulting confusion. State the zone explicitly rather than giving a bare time, and for anything recurring expect the relative gap to move when either side changes clocks — so confirm near the changeover weeks rather than assuming a fixed difference.
A caution specific to this tool: it depends on the zone database in your browser, so a device that has not been updated in a long time may not know about a recent rule change. For anything consequential — a flight, a deadline, a market open — verify against an authoritative source.
Frequently Asked Questions
Does this handle daylight saving time correctly?
Yes. It uses the Intl.DateTimeFormat API backed by your browser's IANA time-zone database, which encodes every region's daylight-saving rules. If you pick a date in January for New York, you get EST (UTC−5); pick a date in July and you get EDT (UTC−4) automatically.
What is the difference between EST and EDT?
EST (Eastern Standard Time) is UTC−5 and applies during winter. EDT (Eastern Daylight Time) is UTC−4 and applies during summer when daylight saving is in effect. The same applies to other time zones — PST/PDT for the US West Coast, BST/GMT for the UK, and so on.
Why use IANA timezone names instead of offsets like UTC+5:30?
Fixed offsets become wrong when daylight saving kicks in. IANA names like "Asia/Kolkata" encode the full history of rules for a region, including exactly when clocks change. A named zone is always correct; a fixed offset is only correct for part of the year in many regions.
Can I convert a specific meeting time rather than the current time?
Yes — change the date and time in the base picker to any date and time you like. The comparison cards update immediately, giving you the correct local time for that specific moment in each zone.
