WatchTimeTime Zone Converter
Pick a date, a time, and two zones. The converter uses your browser's IANA time zone data, so daylight saving transitions on either side are applied automatically — including the date rolling forward or back.
Runs in your browser; nothing you enter is sent anywhere. Without JavaScript, use the manual method below — it gives the same answer.
How to convert time zones by hand
Every conversion is two steps through UTC. First, take the source time and remove its UTC offset to get UTC. Then add the destination's offset. Example: what is 3:00 p.m. in New York (UTC−4 in summer) in Berlin (UTC+2 in summer)? Remove −4: 15:00 + 4 = 19:00 UTC. Add +2: 21:00 — that is, 9:00 p.m. in Berlin. The whole trick is using the offsets that apply on that date, because daylight saving changes them for part of the year.
When the arithmetic crosses midnight, the date moves too. 8:00 p.m. in Los Angeles (UTC−7 in summer) is 3:00 UTC the next day, which is 1:00 p.m. the next day in Sydney during Australian winter (UTC+10). Missing the date change is the single most common conversion error, and it's why this tool always prints the full date with the result.
Common offsets at a glance
| Zone | Standard | Daylight | DST period (approx.) |
|---|---|---|---|
| US Eastern (New York) | UTC−5 | UTC−4 | Mar – Nov |
| US Pacific (Los Angeles) | UTC−8 | UTC−7 | Mar – Nov |
| UK (London) | UTC+0 | UTC+1 | Late Mar – late Oct |
| Central Europe (Berlin, Paris) | UTC+1 | UTC+2 | Late Mar – late Oct |
| India (Mumbai, Delhi) | UTC+5:30 | — | No DST |
| China (Beijing, Shanghai) | UTC+8 | — | No DST |
| Japan (Tokyo) | UTC+9 | — | No DST |
| Eastern Australia (Sydney) | UTC+10 | UTC+11 | Oct – Apr |
Scheduling pitfalls worth knowing
The mismatched-DST weeks. The US changes its clocks two to three weeks before Europe in spring and one week after in autumn. During those windows, every recurring US–Europe meeting silently shifts by an hour for one side. If a weekly call suddenly seems to be at the wrong time in late March or early November, this is almost always why.
Hemisphere flip. Australia and New Zealand run daylight saving during the northern winter. The London–Sydney difference is 11 hours in January but only 9 in July, with brief 10-hour periods in between while one side has changed and the other hasn't.
Times that don't exist or exist twice. On a spring-forward day, the skipped hour (for example 2:30 a.m. in New York on the second Sunday of March) never occurs; on a fall-back day, the repeated hour occurs twice. Calendar software resolves these arbitrarily — avoid scheduling anything between 1 and 3 a.m. local time on transition days.
Frequently asked questions
Why does the converter ask for a date, not just a time?
Because the correct offsets depend on the date. 9:00 a.m. New York → London is 2:00 p.m. for most of the year, but 1:00 p.m. during the weeks when the US has switched to daylight time and Europe hasn't.
What do names like "America/New_York" mean?
They are IANA time zone identifiers — the unambiguous names used by operating systems and databases. They're preferred over abbreviations like "EST" or "IST", which are ambiguous (IST is both India Standard Time and Irish Standard Time).
Can I convert to UTC?
Yes — UTC is in the zone list. Converting to UTC is the standard way to log or store times so they mean the same thing everywhere.
Want to see many zones at once instead? The world clock shows sixteen cities live.