Time by City exists to make international time coordination fast and distraction-free: the exact current time in 172 cities, city-to-city converters, sunrise and sunset, and a meeting planner — with nothing between you and the answer.

Why it was built

Most time sites bury a simple answer under ads, popups and widgets. This site was built around the opposite idea: one clean page per question. What time is it in Seoul? What time is 9:00 in Seoul in New York? When can four cities meet? Each of those gets a fast, quiet page that works the same on a phone in transit as on an office monitor.

How the times are calculated

Every clock is computed in your browser from your device clock and the IANA Time Zone Database — the canonical source of time zone and daylight saving rules used by operating systems, airlines and financial systems worldwide — accessed through the browser's built-in internationalization engine (the Intl API). Daylight saving changes apply automatically on the correct dates, on both sides of every conversion. Sunrise and sunset are calculated astronomically from each city's coordinates using standard solar equations, accurate to within a couple of minutes.

Data accuracy

Because times derive from your device clock, they are as accurate as your device — which on modern phones and computers is synchronized to network time and typically correct to within a second. Time zone rules update automatically with your operating system and browser, so newly legislated changes reach this site without manual edits. City coordinates for sun calculations are curated by hand.

Who runs it

Time by City is designed, built and maintained by an engineer based in Seoul who works across time zones daily and wanted a faster tool than the ones available. It is an independent project: no external investors, no data brokers, no accounts.

Corrections

Spotted a wrong time, a mislabelled zone, or a missing city that deserves a page? Please get in touch with the page URL and what you expected — corrections are usually deployed within days.