Guides

About World Time Converter.

World Time Converter makes it easier to understand someone else’s day. A clear answer, a considerate meeting, a connection worth making.

A new chapter for a familiar address.

This site is a new independent project on worldtimeconverter.com. Our focus is straightforward: make time conversion clear, fast, accessible, and useful. The age of the domain is not a claim that this new service has operated for the same length of time.

How we calculate time

City-based conversions use the browser’s built-in Intl.DateTimeFormat API and its time zone database, based on IANA time zone identifiers. We calculate every location from the same absolute instant, including non-hour offsets and changes of local date.

Our reference content is generated with the build environment’s time zone data. Interactive results use your browser’s data. If a government recently changed its rules, an older device or browser can give a different result until its time zone database is updated. Keep your operating system and browser current.

How content is produced and reviewed

World Time Converter is the named author and publisher of the guides and reference pages. Editorial explanations are maintained alongside the calculation code, automated tests, and source notes so that claims can be checked against the behavior of the tool. Programmatically generated tables are labeled with their reference year or generation date instead of being presented as live observations.

Software-assisted workflows, including AI assistance, may be used for drafting, research, and quality checks. They do not generate the time-zone results shown by the tools. Published guidance is reviewed against primary references such as IANA, ECMA-402, NIST, and RFC 5545; substantive updates receive a new visible review date rather than an artificial freshness change.

Daylight saving transitions

When you enter a local date and time, we check whether it maps to a valid instant in that city. Skipped times are rejected with an explanation. Repeated times let you select the earlier or later occurrence. The visual day can contain 23 or 25 hours when clocks change.

Fixed reference choices are clearly distinguished from local city time. EST remains UTC−5 and PST remains UTC−8. Choose New York or Los Angeles to follow the cities’ seasonal clock rules.

Live clocks and practical limits

The live clocks use your device’s clock. We do not independently synchronize with a time server or claim atomic-clock precision. If your device’s time is wrong, the live display will be wrong by the same amount.

Interactive date entry supports 1900–2100. Historical regional data, especially before 1970, may be incomplete. Future conversions reflect currently installed rules, which governments can change. Verify critical historical or future events against official local sources.

Working hours are a guide

The meeting planner applies your selected working-hours preset to every location. Its optional weekday filter excludes Saturday and Sunday in each city. It does not know personal calendars, public holidays, regional weekend customs, or individual availability. Color shading represents scheduling hours, not astronomical day and night.

Solar times, geography, and city search

Sunrise, sunset, solar noon, and the map’s approximate day–night boundary are calculated with SunCalc. City pages use representative city-center coordinates and a zero-elevation horizon. These calculations do not model mountains, buildings, or local weather and are not suitable for navigation.

The world map uses public-domain Natural Earth geography via world-atlas. The extended search directory comes from city-timezones (MIT license). We validate time zone identifiers at build time. Location names and geographic assignments can be imperfect; use a full IANA identifier if a search result does not match your intended location.

Public holidays and airports

Public holidays come from date-holidays (code ISC; holiday data CC BY 3.0). We show only national public and bank holidays, generated at build time. Regional, state, and many religious or lunar-calendar holidays are not included, and governments can announce changes at short notice, so confirm important dates locally. Holiday shading in the converter marks the whole local calendar day.

Airports on city pages come from public-domain OurAirports data: airports with scheduled service and an IATA code, in the same country, within 80 km of the city coordinates used for solar times. Distances are straight-line estimates.

Weekly previews and saved workspaces

The 12-week preview holds the first city’s local wall-clock time constant. It flags shifts elsewhere, skips nonexistent reference times, and uses the earlier occurrence of repeated times. Calendar downloads remain single events, not recurring invitations. Saved workspaces keep your cities and meeting preferences in browser local storage; pinned times exist only for the current page visit.

Browser storage and analytics

The site serves prebuilt pages using Astro 7 and runs conversion locally in your browser. There is no account, advertising script, or third-party font request. Your chosen cities and clock format are stored on your device. We use stats.admk.com for website analytics. Read the privacy page for details about analytics, shared links, and hosting logs.

Publisher

The company that publishes World Time Converter is identified in our privacy page. You can reach us at [email protected].

Primary references