Changelog

A time and time zone site is never finished. The rules underneath it move — governments change their offsets, the IANA time zone database publishes a new release, and browsers catch up on their own schedule. And sometimes we find that we had it wrong.

Either way, today’s answer may not match the one this site gave the last time you asked, and that difference belongs somewhere you can read it rather than in a quiet fix. Entries that changed ananswer — where the same two dates now produce a different number — are markedChanged an answer.

10 August 2026

Six written pages, this one included

The tools were joined by prose: About, Accuracy,Sources, Time zone changes,Contact and this changelog. They answer what a tool cannot answer about itself: where the time zone data comes from, how far we will vouch for a result, and how to tell us something is broken. No answer moved.

9 August 2026

The site went live

time-hub-express.com started serving pages; until then the tools existed only in a repository. By the close of the day the test suite stood at 1,078 checks, run against three different releases of the world’s time zone and language data — a rule that is right on one release and wrong on another would otherwise reach only the visitors whose devices carry it.

The Pomodoro timer

A Pomodoro timer with focus sessions, breaks, a session history and a daily streak. It is the first tool here that keeps a record rather than a session you resume, which forced two decisions: a tab left idle for two hours does not come back and manufacture four sessions you never sat through, and a session counts towards the day its deadline fell in rather than the day the page noticed — otherwise one ending near midnight in a throttled tab breaks the streak it should extend.

The time zone converter

A converter between any two time zones, and the zone picker it needs. The picker offers every one of the 313 distinct time zones, drawn from a table of 1,500 places covering 247 countries — built from the IANA time zone database (release 2026c), GeoNames place data, and CLDR 48.2.0 for the country names and the label on each zone.

8 August 2026

A squashed month no longer counts as a month

Changed an answer. How long is it from 31 January to 28 February? One reading says a month: add a month to the 31st and you land on the 28th, because February has no 31st. The other says 28 days, because the month only completed by shortening the day to fit. We now give the second answer.

Temporal — the JavaScript standard’s own date API, which this site treats as its reference — changed its convention between versions, and we followed it deliberately. So 31 January to 28 February reads as 28 days, and someone born on 29 February 2008 is 17 on 28 February 2026 and turns 18 on 1 March. It applies only on an exact landing: 31 January to 1 March is still one month and one day, and adding a month is unchanged.

The calendar arithmetic under the date tools was corrected

Changed an answer. The function that counts years, months and days between two dates disagreed with the reference implementation on a class of month-end dates: start on a day of the month that some later month does not have, and the two could part company. Measured against 1,020,000 date pairs aimed at those boundaries, it was wrong on 2,259. It now agrees on all of them, and that comparison runs on every change.

It survived because an earlier check had run 40,000 randomly chosen date pairs and found nothing — a genuine measurement over a sample that could barely reach the defect, since random dates land there about seven times in ten thousand. More in Accuracy.

The date difference calculator

A calculator for the gap between two dates in days, weeks and months, with two further modes: add or subtract a span from a date, and work out an age from a date of birth.

The online timer

A countdown timer with presets, a sound when it reaches zero, and a full-screen view for reading across a room.

The stopwatch

A stopwatch with laps, each lap’s own duration beside the running total. The first interactive tool here, and it set the pattern: elapsed time is the difference between two readings of your device’s clock, not a count of screen refreshes, so backgrounding the tab costs you smoothness and no accuracy.

1 to 3 August 2026

The foundation, with nothing yet to click

Three days of work a visitor could not see. The tested date and time core came first — calendar arithmetic, conversion between zones, and a formatting layer that pins every date here to one presentation, so 4 March 2026 is never written as 03/04/2026 or04/03/2026.

Light and dark themes landed with a contrast check that reads the stylesheet itself, because an automated accessibility score renders one theme and would award full marks to an unreadable dark palette. So did the working-week model, which treats the weekend as something you state rather than something we assume — Saturday and Sunday is not the working week everywhere. The storage layer came last. Saved in this browser only. Clearing site data or switching devices will erase it.

What is coming

Four of the planned tools are not built yet: a countdown to a date or an event, a world clock, a meeting planner showing the hours that overlap across several zones, and a business-days calculator. They are named here but not linked, because a link to a page that does not exist is its own small lie.

Time zone rules change on their own schedule. When one moves an answer here, it is written up inTime zone changes as well as recorded on this page. If you find something wrong, please tell us — a report naming the two dates or two zones you used is worth far more than one without, and the correction appears here, dated like everything else.