Time Zone Converter
A time zone converter that shows one moment in every city you care about at once — with UTC offsets, daylight saving flags and a working-hours strip that makes a workable meeting slot obvious.
How to use Time Zone Converter
- Pick the zone you are working from and set the date and time, or press Now.
- Add every other city you need — colleagues, clients, family — and they all update together.
- Read each row for the local time, the UTC offset, the zone abbreviation and whether it is a different calendar day.
- Drag the marker across the meeting planner to find an hour that is inside working hours everywhere.
- Copy the summary line and paste it straight into an email, ticket or chat message.
About Time Zone Converter
Scheduling across time zones fails in predictable ways: someone forgets that the United States and Europe change their clocks on different weekends, someone assumes India is a whole number of hours off, or a meeting lands at 06:00 for the one person who did not speak up. A good time zone converter prevents all three by showing the same instant everywhere at once, with the offset, the abbreviation and the calendar date spelled out rather than left to mental arithmetic.
The conversions here come from the Intl.DateTimeFormat API, which is backed by the IANA time zone database built into your browser and updated with it. That matters because zone rules are political, not astronomical: countries change offsets, abolish daylight saving, and occasionally shift the date line. Working from the same database your operating system uses means a date in the future is calculated with the rules that will actually apply then — including the awkward fortnight each spring and autumn when Europe and North America are temporarily an hour closer together.
The meeting planner turns that data into a decision. Each city gets a 24-hour strip shaded for working hours, evening hours and sleep, and a marker you can drag across the day; a column that is green in every row is a time everyone can genuinely make. When you have found one, the copyable summary writes it out in every zone so the invitation cannot be misread. Your chosen cities are remembered locally, so the page opens on your own set of zones every time.
Frequently asked questions
How does the converter handle daylight saving?
Automatically and for the date you choose, not just for today. Conversions use the browser's IANA time zone database through the Intl API, so a meeting set for late March is calculated with the rules that apply on that date. Any zone currently observing summer time is flagged in its row.
Which time zones are supported?
Every zone in the IANA database your browser ships with — around 400 named zones covering all inhabited regions, plus UTC. Search by city (“Auckland”), by region (“Europe”) or by the full zone name. Older browsers without the full list fall back to a curated set of roughly a hundred major zones.
What do the colours in the meeting planner mean?
Each row is a 24-hour strip of that city's local day. Green hours are working hours, 09:00 to 17:00 local. Amber hours are early or late but reachable. Dim hours are night, roughly 22:00 to 07:00. A column that is green in every row is a slot that suits everyone.
Why does a city show a different date?
Because the international date line means a single instant falls on different calendar days around the world. When a zone is on the previous or next day relative to your source zone, the row shows a +1 or −1 badge so you never book a meeting for the wrong day.
What does an offset like UTC+05:30 mean?
It is how far that zone is ahead of or behind Coordinated Universal Time — the modern successor to GMT. India is UTC+05:30, so 12:00 UTC is 17:30 in Kolkata. Offsets that are not whole hours are common: India, Iran, parts of Australia and Nepal all use half-hour or 45-minute offsets.
Is my location or schedule sent anywhere?
No. Every calculation runs in your browser using data it already has, and your chosen zones are saved only in local storage. Nothing about your meetings, your location or your contacts leaves the device.
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