Offsets are resolved for the local date entered, rather than treating the current offset as permanent. This matters around daylight saving transitions and when locations change rules on different dates.
The converter uses the IANA time-zone database available in the browser. A local clock time skipped during a spring-forward transition is reported as invalid instead of silently changing the requested time.
Questions
London to New York FAQ
What is the time difference from London to New York?
New York is currently 5 hours behind London. City offsets can change with daylight saving time, so use the date-specific converter for another date.
How do I convert London time to New York?
Choose the local date and time in London. The converter resolves that wall-clock time with Europe/London, then formats the same instant in America/New_York.
Does London to New York change with daylight saving time?
It can. At least one selection uses date-aware city rules, and the two locations may start or end daylight saving time on different dates.