A device-clock action is a convenience
When you choose a current-time action, the browser can supply an instant from the device’s clock. That is useful for starting a comparison, but it is not an independent precision time signal. A wrong system clock or date can produce a wrong starting instant even when the conversion rules are applied correctly.
Use an explicit date for a planned event
For a meeting next month, enter the actual local date and time in the intended base city. A current comparison does not determine a future offset. London and New York, for example, have different gaps during parts of their clock-change seasons. The date of the event must drive the conversion.
Check the year as well as the month and day. This build supports planning years 2026–2035. A date outside the supported range should produce a clear limit rather than a confident-looking extrapolation from incomplete data.
Distinguish the device clock from the rule database
The device supplies an instant when requested. The bundled IANA 2026f data supplies the rules used to display that instant in each selected zone. Those are separate inputs. Updating a device clock does not update this build’s bundled rule version, and updating rule data does not correct an inaccurate device clock.
Read static examples as examples
The eight-city reference on this site is dated 27 October 2026 at 13:00 UTC. City pages also include selected January, July, October, and November examples. They help explain seasonal differences and date boundaries. They are not labeled as current time and should not be used to decide what time it is now.
Make a result reproducible
Keep the cities or IANA identifiers, local date and time, chosen ambiguity resolution, meeting length, and data version with an important plan. A project JSON backup preserves the editable settings. A timetable records the displayed result, while an ICS file records resolved events. Together they make a surprising result easier to check later.
Confirm in the calendar you will use
Before relying on an imported event, compare the calendar’s display zone, the local date, and the duration. Use the planner to understand the conversion, then confirm the arrangement with the participants. The site does not provide alarms or synchronize calendars after the download.
Sources
Follow the original references for the rules and formats used in this guide.