What does the date and time zone converter do?
Scheduling across time zones is error-prone: offsets change with daylight saving time (DST), countries start and end DST on different dates, and some zones are offset by 30 or 45 minutes. This converter takes a date and time in any IANA time zone — such as America/New_York or Asia/Kolkata — and shows the same moment in as many other zones as you like, with the UTC offset, abbreviation, DST status and a +1 day marker when the date changes.
Under the hood it uses your browser's built-in time zone database (the same one used by calendars and operating systems), so historical and future DST rules are applied for the exact date you pick. Edge cases are handled explicitly: if you choose a time that is skipped when clocks spring forward, or one that happens twice when they fall back, the tool tells you and shows how it was resolved.
Below the converter are two date calculators: one counts the days, weeks, months, years and business days between two dates; the other adds or subtracts days, weeks, months, years or working days from a date. Everything runs locally in your browser.
How to use the Date & Time Zone Converter
- Pick a date and time, or click Now. The source time zone defaults to your own.
- Read the equivalent time in each listed zone. Use the search box to add cities and the × button to remove them — your list is remembered.
- Click the swap icon on any row to make that zone the new source, or Copy all to paste the schedule into an email or calendar invite.
- Scroll down to count the days between two dates, or to add and subtract days, weeks, months or business days.
Example: a meeting at 9:00 in New York
Thursday 1 October 2026, 09:00 in America/New_York (EDT, UTC−04:00) is:
UTC 13:00 Thu, 1 Oct 2026 UTC+00:00
London 14:00 Thu, 1 Oct 2026 UTC+01:00 BST
Kolkata 18:30 Thu, 1 Oct 2026 UTC+05:30 IST
Tokyo 22:00 Thu, 1 Oct 2026 UTC+09:00 JST
Sydney 23:00 Thu, 1 Oct 2026 UTC+10:00 AESTDaylight saving time gaps and overlaps
When clocks spring forward, an hour of local time never happens — in New York, 02:30 on the second Sunday of March does not exist. When they fall back, an hour happens twice. A naive converter silently picks an arbitrary answer; this one moves skipped times forward by the length of the gap and, for repeated times, uses the first occurrence while showing the second. That matches how most calendar apps and the JavaScript Temporal API behave.
Because Europe, North America and Australia change their clocks on different dates, the gap between two cities can vary through the year. Always convert for the specific date of the meeting, not "today".
How the date difference is counted
- By default the end date is not counted: from Monday to Friday is 4 days. Tick Include the end date to count both ends (5 days).
- Months and years are counted as calendar months; 31 January plus one month is 28 (or 29) February.
- Business days are Monday to Friday. Public holidays vary by country and are not excluded.
- For server timestamps and epoch seconds, use the Unix Timestamp Converter.
Frequently Asked Questions
How does the converter know about daylight saving time?
It uses the IANA time zone database that ships with your browser through the Intl.DateTimeFormat API. That database contains the historical and scheduled DST rules for every region, so the offset is correct for the date you choose.
What is the difference between UTC and GMT?
For everyday use they show the same time. UTC is the atomic-clock based standard used by computers and aviation; GMT is a time zone used by the UK in winter. London switches to BST (UTC+01:00) in summer, while UTC never changes.
Why do some zones not show an abbreviation?
Many regions have no widely recognised abbreviation, so browsers only provide a form like GMT+4. In that case the tool shows just the UTC offset, which is unambiguous — abbreviations such as IST or CST can mean several different zones.
How many business days are between two dates?
Enter both dates in the Date difference calculator. It counts Monday to Friday between them (excluding the end date unless you tick the option). Subtract public holidays in your country manually.
How do I schedule a WordPress task at a specific time?
WordPress cron uses the site time zone set under Settings → General, while server cron jobs usually run in UTC. Convert the time here, then build the schedule with the Cron Generator.
Is my data sent anywhere?
No. All conversions and calculations happen in your browser. Your list of time zones is saved only in your browser's local storage.