Time Zone Calculator
Convert a date and time from one time zone to another. Pick from 34 zones covering every UTC offset from −12:00 to +14:00 — including the half- and quarter-hour zones like India and Nepal — and see the converted time, the offset difference, and whether the date rolls over.
Offsets are standard time. During daylight saving time, zones that observe it shift one hour closer to UTC+14 — see the table below.
How time zone conversion works
Every zone is an offset from Coordinated Universal Time (UTC). To convert, the calculator turns your input into UTC by removing the source offset, then applies the destination offset: a 14:30 meeting in New York (UTC−5 standard) is 19:30 UTC, which is 19:30 in London (UTC+0) and 4:30 AM the next day in Tokyo (UTC+9). Offsets aren’t always whole hours — India runs at +5:30, Nepal at +5:45, and Newfoundland at −3:30.
The DST caveat: this tool uses fixed standard offsets. Roughly 70 countries move their clocks seasonally, so in summer the U.S. East Coast is really UTC−4 and London UTC+1. When both places shift together the difference is unchanged; when only one observes DST (Arizona, most of Asia, all of China and Japan), adjust the result by an hour.
How it’s calculated
Converted time = local time − from-offset + to-offset, computed on a UTC timeline so month ends, leap days, and date-line crossings resolve correctly. Zone list covers all 25 whole-hour offsets plus the 30- and 45-minute zones in use today (UTC−12:00 to UTC+14:00).
Standard-time offsets only — verify DST for the specific date and both locations before booking anything irreversible.
Standard vs. daylight offsets for major zones
| Zone | Standard | DST | DST months (approx.) |
|---|---|---|---|
| U.S. Eastern (New York) | UTC−5 | UTC−4 | Mar–Nov |
| U.S. Central (Chicago) | UTC−6 | UTC−5 | Mar–Nov |
| U.S. Mountain (Denver) | UTC−7 | UTC−6 | Mar–Nov (Arizona stays −7) |
| U.S. Pacific (Los Angeles) | UTC−8 | UTC−7 | Mar–Nov |
| UK & Ireland | UTC+0 | UTC+1 | Mar–Oct |
| Central Europe (Paris, Berlin) | UTC+1 | UTC+2 | Mar–Oct |
| India | UTC+5:30 | — | No DST |
| China | UTC+8 | — | No DST |
| Japan & Korea | UTC+9 | — | No DST |
| SE Australia (Sydney) | UTC+10 | UTC+11 | Oct–Apr |
| New Zealand | UTC+12 | UTC+13 | Sep–Apr |
Worked example
2:30 PM on July 15, 2026 in U.S. Eastern (UTC−5) converts to 7:30 PM the same day in London (UTC+0) — a +5h difference. The same moment in Tokyo (UTC+9) is 4:30 AM on July 16, and in Delhi (UTC+5:30, from Chicago UTC−6) a 2:30 PM call lands at 2:00 AM the next day. In July both New York and London are actually on DST (−4 and +1), so their 5-hour gap is unchanged.
Common mistakes
- Forgetting DST — a zone that observes it is one hour closer to UTC+14 in its summer.
- Assuming every offset is a whole hour; India (+5:30), Iran (+3:30), and Nepal (+5:45) are not.
- Missing the date change — a U.S. evening is usually tomorrow morning in Asia and Australia.
- Scheduling by zone abbreviation (“CST” means three different zones worldwide) instead of a city.
Where it is used
- Scheduling calls and meetings across offices, clients, or family abroad.
- Converting webinar, launch, or game release times to your local clock.
- Planning flight arrivals and layovers across the date line.
- Setting deadlines in UTC for distributed teams.
Frequently asked questions
Does this handle daylight saving time?
It converts using fixed standard offsets, like most quick reference tables. If one of your two locations is currently on DST, shift the result one hour; if both shift together (e.g., New York and London), the difference is usually unchanged. The table above lists common DST windows.
Why do some zones differ by 30 or 45 minutes?
Countries choose offsets to fit their geography and politics. India and Sri Lanka use UTC+5:30, Iran +3:30, Newfoundland −3:30, and Nepal +5:45 — the world’s only +:45 zone alongside the Chatham Islands (+12:45).
What is the biggest possible time difference?
26 hours — between UTC−12 (Baker Island) and UTC+14 (Kiritimati). It can be 2:00 AM Tuesday on Kiritimati while it is still midnight Monday on Baker Island.
What is the difference between GMT and UTC?
For everyday use they show the same clock time. GMT is a time zone (mean solar time at Greenwich); UTC is the atomic-clock standard the world calibrates against. Aviation and computing use UTC.
Why does my phone show a different result?
Phones apply live DST rules for the exact date. If your result differs by exactly one hour, one of the two zones is on daylight time — this tool deliberately shows standard offsets so the math is predictable year-round.