ZoneMapzone World Clock

Show HN: ZoneMapzone World Clock

Operating in show hn launch, ZoneMapzone World Clock operates.

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I built this because I kept needing to answer "when is 3pm EST for my teammate in Singapore" and none of the existing tools felt right for me - they're mostly lists. I wanted a map where time differences are spatially obvious.A few things that were technically interesting to build: The day/night terminator. It's not just a shaded half-sphere. I implemented a simplified USNO solar declination algorithm, computing the subsolar point for a given UTC timestamp, then tracing the great-circle terminator and sampling which side each pixel falls on. It renders pixel-by-pixel onto a Canvas overlay above the SVG map. During drag it bypasses React's render cycle entirely and draws directly on the canva

The company sits in the show hn launch segment, where it competes on its core product or service.

It is recorded at the Show HN launch stage.

Website: zonemap.live