World Time Converter
Convert times across global time zones. Daylight saving aware. Instant, browser-based — no servers, no uploads.
About the World Time Converter
This world time converter runs entirely in your browser using the standard Intl.DateTimeFormat API with IANA time zone identifiers (such as America/New_York or Asia/Tokyo). When you enter a source date and time and pick a source time zone, the tool treats the input as wall-clock time in that zone, computes the corresponding UTC instant, and then formats that instant in the destination time zone. Because the conversion relies on the browser's built-in time zone database, daylight saving time (DST) transitions are handled automatically.
What is a time zone?
A time zone is a region that observes a uniform standard time, usually described as an offset from Coordinated Universal Time (UTC). The world is divided into roughly 24 one-hour offsets, but many zones use 30- or 45-minute offsets (for example India is UTC+5:30 and Nepal is UTC+5:45). IANA time zone identifiers — like Europe/Paris or Australia/Sydney — encode both the base offset and the historical rules for daylight saving, so they are the most reliable way to convert times.
What is UTC?
UTC (Coordinated Universal Time) is the primary time standard by which the world regulates clocks and time. It is not a time zone in the political sense, but rather a reference point. Every civil time zone can be expressed as UTC plus or minus an offset. For example, when it is 12:00 UTC, it is 08:00 in New York (UTC−4 during DST) and 21:00 in Tokyo (UTC+9, no DST).
What is daylight saving time (DST)?
Daylight saving time is the practice of advancing clocks by one hour during the warmer months so that evenings have more daylight. Not every country observes DST — for example Japan, China, and most of Africa do not. The start and end dates also differ: the United States shifts on the second Sunday of March and the first Sunday of November, while the European Union shifts on the last Sundays of March and October. Because the offset of a zone can change between the source moment and the target moment, the converter recomputes the offset for each timestamp independently.
How to convert times with this tool
- Pick the source date and time using the datetime field. It defaults to the current moment.
- Choose the source time zone (where the entered time is the local wall-clock time).
- Choose the destination time zone you want to convert into.
- The converted time updates live as you change any input — press Convert for a confirmation toast.
Frequently asked questions
Does this tool handle daylight saving time? Yes. The browser's Intl API applies the correct DST rules for each IANA zone at the given instant.
Does this tool upload my data? No. All conversion happens locally in your browser. No date or time values are sent to a server.
What time zones are supported? Any IANA time zone that your browser ships. This tool exposes sixteen of the most common world cities plus UTC; you can extend it freely with other identifiers such as America/Sao_Paulo or Pacific/Honolulu.
Why does the offset shown look unusual? Some zones use 30- or 45-minute offsets (for example Asia/Kolkata is UTC+5:30 and Asia/Kathmandu is UTC+5:45). The display reflects the true civil offset, not a rounded whole hour.
Can I convert a time in the past or future? Yes. Historical conversions use the historical offset rules at that instant; future conversions use the currently scheduled rules.