SuCalc
Time, Date & Work

Time Zone Converter

Updated Aug 24, 2026 Reviewed Aug 24, 2026
Convert one local date-time to up to four IANA time zones with daylight-saving offsets, date changes, and ambiguity controls.

World time conversion

Convert one instant across locations

Type a city-based IANA identifier such as Europe/London; UTC is also supported.

Used only when the chosen local time repeats or does not exist.

Every row is the same instant
Only the wall-clock representation, calendar date, UTC offset, and abbreviation change between locations.

Result

Calculation summary

Enter values to see the result

Your result, breakdown, assumptions, and warnings will appear here.

World-clock preview

Same instant, different clocks

Live preview
Same instant, different clocksAsia/Shanghai: 09:00:00 AM. Europe/London: 02:00:00 AM.Asia/Shanghai09:00:00 AMEurope/London02:00:00 AMCalendar date shift0d
The first target is highlighted here; the submitted result includes every selected target zone.

How to use this calculator

  1. 1Enter the source wall-clock date and time.
  2. 2Choose its IANA source zone and one to four target zones.
  3. 3Convert to compare the same instant across locations.

Formula

Target local time = source instant represented in target IANA time zone

The source wall time is resolved once; changing zones then preserves the exact instant.

Calculation steps

  • Validate the local date-time and IANA identifiers.
  • Resolve DST ambiguity using the selected policy.
  • Create one exact instant from the source.
  • Represent that instant in every target zone.
  • Show offsets and calendar-day shifts.

Worked example

09:00 in Shanghai is 01:00 in London when London is on UTC+00:00; seasonal rules can change the offset.

Assumptions

  • All target rows represent exactly the same instant.
  • IANA rules, rather than fixed offsets, determine daylight-saving behavior.
  • Future civil-time rules can change after publication.
  • Compatible resolves repeated times earlier and skipped times later.
  • Displayed abbreviations depend on locale and browser data.

Sources

Frequently asked questions

Does this account for daylight saving time?

Yes. IANA zone rules are applied for the selected date.

Why use a city zone instead of UTC+8?

A named zone contains historical and seasonal rule changes; a fixed offset does not.

What does +1 day mean?

The target local calendar date is one day after the source local date, although both rows are the same instant.

Can I compare several locations?

Yes. Add up to four unique target time zones.

Can future results change?

Yes. Governments can change civil-time rules, and IANA data is updated accordingly.

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