About DateTimeX

DateTimeX is a free world clock and timezone toolkit: live clocks for every major timezone, a timezone-pair converter, a meeting planner, a Unix timestamp converter, a daylight-saving tracker, and a handful of reference guides — all built to answer one recurring, oddly hard question as accurately as possible: "what time is it there, really?"

Why This Site Exists

Timezone math looks simple until it isn't. Offsets aren't all whole hours — India runs UTC+5:30, Nepal runs UTC+5:45. Daylight saving isn't decided per timezone but per country, and sometimes per region within a country, so the gap between two places can quietly shift by an hour for a week or two each spring and autumn when their DST switchover dates don't line up. A quick web search or a stale spreadsheet gets this wrong often enough to cause real problems — a missed call, a wrong delivery estimate, a confused meeting invite. DateTimeX exists to make getting it right the path of least resistance.

How It's Built

Every clock, conversion, and daylight-saving status on this site is computed live from the IANA Time Zone Database — the same timezone data built into browsers, phones, and servers, maintained and updated by the people who track DST law changes worldwide. Nothing here is a hand-typed fact that can quietly go stale: when a government changes its clock-change rules, browser vendors update that shared database, and every page on this site reflects the new rule automatically the next time it loads. The site itself is static — no accounts, no backend database, no server-side processing of your data. Everything runs in your browser.

How We Verify Our Data

Nothing on DateTimeX is a fact typed once and left alone. Live clocks, offsets, and DST status come straight from the IANA Time Zone Database — but the handful of things that genuinely can't be computed live, like stock exchange trading hours and exchange holiday calendars, are hand-researched against each source's own primary, official calendar rather than a general national-holiday proxy, and re-verified on a documented schedule instead of being left to go stale silently.

For example, when the Tokyo Stock Exchange changed its closing time from 3:00pm to 3:30pm JST in November 2024 — its first change in 70 years — that fact was verified through the exchange's own announcement before it went into this site's data, not assumed from an older reference.

When exchange holiday calendars were added, two off-the-shelf data sources were tested and rejected first, specifically because they were wrong: a popular open-source package's US holiday data excluded Good Friday even though the NYSE actually closes for it, and its China holiday list mixed in non-market observances. Both errors were caught by comparing the data against each exchange's own published calendar before anything shipped, not after.

Every hand-maintained data set on this site — currently just exchange session hours and holiday calendars — carries a visible "current as of" date on the page itself and a documented annual refresh commitment, rather than being presented as permanently correct.

Who Runs It

DateTimeX is an independently built and maintained project, kept free and ad-supported rather than paywalled or subscription-based. If something looks wrong, is confusing, or is missing a timezone or city you need, the Contact page goes straight to the person maintaining the site.