Show HN: A Simple Server to Match Long/Lat to a TimeZone
Published on: 2025-06-30 12:43:50
A Server for Matching Long/Lat to Timezone
Overview
This project is a fairly simple PHP project, designed to accept the GeoJSON output of the Timezone Boundary Builder Project, and provide a simple API, for matching longitude/latitude locations with timezones.
Send in a long/lat, and get back a string, with the standard TZ time zone designator of the timezone that covers that point.
This is the GitHub repo for this project
What Problem Does This Solve?
Unfortunately, time zones are not a simple "I'm at this longitude, so it must be this time." They are political constructs.
Here's why we can't just do a simple longitude match:
Image Source: Wikimedia Commons
We address this by using the rendered result of this great project, which is an effort to build a "living document" map of all the world timezones, as a shapefile (a file that can project polygons over a digital map), and locating a geographic point, within those shapes.
How This Works
We provide a very basic PHP server
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