Time zone converter

Start with the question you actually have: when it is 5:00 PM on September 8, 2026 in Los Angeles, what time is it in Kolkata? The converter gives the answer as a complete sentence, then shows the selected locations, their IANA IDs, the active abbreviations and UTC offsets, and whether the target falls on the previous or next calendar day. It can use the time zone your browser reports as a starting point, but that is a time-zone setting—not a precise location and not a request for geolocation permission.

For that example, the result is 5:30 AM on September 9 in Kolkata (IST, UTC+05:30). Los Angeles is observing PDT (UTC−07:00) on that date, not PST. The difference is therefore 12 hours 30 minutes, and the date rolls forward by one day. Naming the active rule beside the answer prevents the common mistake of applying a standard-time abbreviation to a daylight-time date.

The IANA Time Zone Database uses location-based identifiers such as America/Los_Angeles, Europe/London, Asia/Kolkata, and Australia/Eucla. An ID describes a place’s history of offset and daylight-saving rules; it is more useful for a saved event or software configuration than UTC-7, which says nothing about future changes, or PST, which can be ambiguous.

The search field may accept familiar words and abbreviations, but an abbreviation is only a shortcut to a choice. IST can refer to India, Ireland, or Israel; CST can refer to several regions; and PST may be used for different places or as a loose synonym for a seasonal Pacific label. Confirm the city or region, read the IANA ID, and then check the offset shown for the date you entered. The page does not create a separate indexable page for every pair: one canonical converter handles the choice you made.

Time-zone conversion is date-aware. A place can move between standard and daylight time, and neighboring places can change on different dates. That means the difference between two locations can change even when neither city has moved. The result reports the active abbreviation and offset instead of presenting a timeless “hours ahead” claim.

Two edge cases deserve a visible explanation:

• During a spring-forward change, some local wall-clock times do not exist. A request for one of those times cannot identify a real instant without a policy.
• During a fall-back change, some local times occur twice. The two choices have different offsets and may map to different UTC instants.

The TC39 Temporal time-zone guidance describes these gaps and overlaps and the earlier, later, and reject choices. This converter keeps the choice explicit rather than silently moving the time and giving you a plausible-looking but different appointment.

These examples use named IANA zones and show why the date belongs in the question:

• London to Kolkata in winter: 9:00 AM on January 15, 2026 in Europe/London becomes 2:30 PM the same day in Asia/Kolkata (GMT → IST). London is on standard time.
• London to Kolkata in summer: 9:00 AM on July 15, 2026 in Europe/London becomes 1:30 PM the same day in Asia/Kolkata (BST → IST). London’s daylight time makes the difference one hour smaller.
• Kathmandu to Eucla: 9:00 AM on July 15, 2026 in Asia/Kathmandu becomes 12:00 PM the same day in Australia/Eucla (+05:45 → +08:45). Not every offset is a whole number of hours.

Use these as sanity checks, not as a substitute for entering your own date. Rules can be revised, and a browser may not yet contain a very recent change.

The conversion is performed in your browser with its built-in internationalization and time-zone implementation. No file upload, account, IP-based location lookup, or server-side calculation is needed. The selected date, time, and zones are inputs to this page’s local tool flow; they are not sent to a processing API. This is useful for private meeting details, but it is not a promise that every other site feature has the same data-handling purpose, so the site’s privacy policy remains the right place to review broader disclosures.

The browser/operating-system time-zone data is also a boundary of accuracy. The IANA database changes when governments alter rules, while browsers and operating systems distribute those updates on their own schedules. JavaScript’s Intl time-zone APIs generally do not expose one portable database version for a page to report. For a very recent rule change, compare the IANA ID and date, update the device, and verify the result against an authoritative local source.

If you are preparing a schedule from copied text, Text statistics can help inspect its length and line structure. If you are constructing a shareable query string, URL encode explains the safe encoding step. For a broader visual comparison after you have decided what data to show, the chart generators can render a local chart from supplied data. These links are adjacent utilities, not alternate time-zone calculation engines.

The conversion method follows the browser’s IANA-backed time-zone behavior rather than hand-written offset arithmetic. The explanatory boundaries are informed by the IANA Time Zone Database, MDN’s Intl.DateTimeFormat documentation, and TC39’s time-zone documentation. Those sources describe the data and concepts; the page’s answer is calculated locally for the date and zones you choose.