About builtdate
builtdate is a fast, accurate toolkit for time and dates. Convert between any of 56 world time zones, check the live local time in 350+ cities, plan meetings across the globe, and count down to any date or holiday — all free, instant, and without a sign-up.
What you can do
- Convert any time and date between two zones, with daylight saving and day rollovers handled automatically.
- Check the live local time in 350+ cities, with a fullscreen big-screen view.
- Count down to holidays, years, months, and any custom date or event you name.
- Plan meetings across time zones, and work out date differences and business days.
- Embed a converter, world clock, or countdown on your own site.
How it works
The converter reads each zone’s real offset for the exact date you choose, using your browser’s built-in IANA time zone database. That means daylight saving is always applied correctly — for past and future dates, and for the Southern Hemisphere, where summer falls in December. Quick-reference charts use each label’s fixed standard offset as a stable baseline, and are marked as such.
Meet the team
A small, focused team building tools we wanted to use ourselves.
Zayn
Founder & lead developer
Created builtdate and leads its architecture, performance, and the time-zone and daylight-saving accuracy at its core.
Omar
Full-stack developer
Builds the engine behind the converter, world clocks, and countdowns — from the data pipeline to the programmatic pages.
Zack
Frontend developer & designer
Shapes the interface and design system, and crafts the small interactions that make every tool feel fast and effortless.
Accuracy & limitations
Time zone laws can change at short notice. We rely on the IANA time zone database delivered through your browser and operating system, which is kept up to date by your device. Even so, please confirm critical timings — flights, exams, interviews, legal deadlines, or live events — against an official source.
Spotted something off, or want a zone, city, or feature added? Get in touch.