Time Zone Converter
Convert a date and time between world time zones, DST aware.
Quick answer
- Formula: UTC instant = wall time in source zone (offset resolved iteratively for DST); result = that instant rendered in the target zone
- Worked example — Converted date & time: January 15, 2026, 5:00 PM GMT (full example below).
Time Zone Converter
| Converted date & time | January 15, 2026, 5:00 PM GMT |
| Offset difference (to − from) | +5 hours |
Noon in New York on January 15, 2026 is 5:00 PM in London the same day — London is 5 hours ahead in winter.
Pick a date and time in one time zone and see the same moment in another zone, together with the offset difference between the two zones on that date.
The conversion uses the IANA time zone database, so daylight saving time is applied correctly for the date you choose — January dates use standard time in the northern hemisphere, for example.
The formula
Worked example
Noon in New York on January 15, 2026 is 5:00 PM in London the same day — London is 5 hours ahead in winter.
The example is pre-loaded in the result panel — press Calculate with your own numbers to replace it.
Frequently asked questions
Why does the offset change with the date?
Many zones move their clocks forward in summer (daylight saving time) on different dates, so the difference between two zones is not constant through the year. Always convert using the actual date of the event.
What does the offset difference mean?
It is the target zone's UTC offset minus the source zone's offset at that moment. A positive value means clocks in the target zone read later than in the source zone.
Category: Date & Time calculators
Sources & methodology
This calculator applies the formula shown on this page exactly as written, using the standard definitions for its inputs. Results are computed from the values you enter — no data is stored — and are rounded only for display.
Content last reviewed by CalcHub Editorial.
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