About WatchTime Online
Why this site exists, who builds it, and how it actually works under the hood.
WatchTime Online started from a small annoyance: every time-and-date tool I tried to use online buried a thirty-second answer under autoplaying video, three pop-ups, and a page of SEO filler before the actual number showed up. I wanted a world clock that just showed the time, and an age calculator that just told me my age — so I built them.
What this site is
WatchTime Online is a set of small, single-purpose tools for questions involving time and dates: what time it is somewhere else, how old someone is, how many days stand between two dates, what a Unix timestamp means, when two people's work hours overlap. Each tool lives on its own page, does one job, and tries to do it well rather than trying to be a do-everything dashboard.
I'm a designer and developer, and this is one of a handful of small, focused sites I build and maintain on my own — the kind of project that exists because I wanted the tool myself and couldn't find a version I liked using.
How the tools actually work
Nothing you type is sent anywhere. Every calculation — a date difference, an age, a converted time zone — runs as JavaScript in your own browser. There's no backend processing your birthday or your meeting times; the page does the arithmetic locally and shows you the result. That's not a privacy feature bolted on afterward, it's just the simplest way to build a calculator: the browser already has everything it needs.
Time zones come from your browser's own data. The world clock, the zone converter, and the meeting planner all lean on the IANA time zone database that ships with every modern browser and operating system — the same reference data used by Windows, macOS, iOS, and Android. That means daylight saving transitions, historical offset changes, and edge cases are handled by data your browser vendor keeps current, not by a lookup table I'd have to maintain by hand and inevitably let go stale.
The explanations are not filler. Underneath most tools you'll find a section on how the calculation actually works — why ISO week numbers sometimes hit 53, why "one month after January 31" is a judgment call, why a countdown can look "wrong" across a daylight-saving change. I write those because date math has more sharp edges than people expect, and I'd rather you understand the number than just trust it.
What's next
The site is still young and growing. I'm working through adding more tools, expanding the explanatory guides, and generally making the site faster and easier to navigate. If there's a time or date question you keep having to solve by hand, it's worth telling me about it — most of the tools here started as exactly that kind of request, even when I was the one making it.
