gpx1.4 KB

GPX — Timestamps With a UTC Offset Instead of Z

The same eight points timestamped with a +01:00 offset rather than the usual Z. The digits are identical to the reference track, so a parser that strips the offset and assumes UTC produces times that are wrong by exactly one hour — a silent error that only shows up when two traces are merged.

Geospatial Time-series data Error handling

Preview — first 46 linesgpx

<?xml version="1.0" encoding="UTF-8"?>
<gpx version="1.1" creator="Novus Examples geospatial fixtures" xmlns="http://www.topografix.com/GPX/1/1">
  <metadata>
    <name>Kestrel Bay Coast Road</name>
    <desc>Synthetic GPS trace over an invented territory.</desc>
    <time>2026-01-01T09:00:00Z</time>
  </metadata>
  <trk>
    <name>Coast Road, local time</name>
    <trkseg>
      <trkpt lat="47.064024" lon="-12.482008">
        <ele>12.1</ele>
        <time>2026-01-01T09:00:00+01:00</time>
      </trkpt>
      <trkpt lat="47.066181" lon="-12.478086">
        <ele>18.9</ele>
        <time>2026-01-01T09:00:15+01:00</time>
      </trkpt>
      <trkpt lat="47.068297" lon="-12.474186">
        <ele>24.8</ele>
        <time>2026-01-01T09:00:30+01:00</time>
      </trkpt>
      <trkpt lat="47.070538" lon="-12.470269">
        <ele>30.5</ele>
        <time>2026-01-01T09:00:45+01:00</time>
      </trkpt>
      <trkpt lat="47.072646" lon="-12.466428">
        <ele>36.7</ele>
        <time>2026-01-01T09:01:00+01:00</time>
      </trkpt>
      <trkpt lat="47.074851" lon="-12.462489">
        <ele>41.5</ele>
        <time>2026-01-01T09:01:15+01:00</time>
      </trkpt>
      <trkpt lat="47.077037" lon="-12.458586">
        <ele>46.1</ele>
        <time>2026-01-01T09:01:30+01:00</time>
      </trkpt>
      <trkpt lat="47.079139" lon="-12.45468">
        <ele>49.4</ele>
        <time>2026-01-01T09:01:45+01:00</time>
      </trkpt>
    </trkseg>
  </trk>
</gpx>

Specifications

Crs: WGS 84 (EPSG:4326)
Encoding: UTF-8
Line Endings: LF
Seed: 20260807
Jitter Sigma Degrees: 0.000025
Start Time: 2026-01-01T09:00:00Z
Sample Interval Seconds: 15
Format: GPX 1.1
Trackpoints: 8
Time Zone Offset: +01:00
Equivalent Utc Start: 2026-01-01T08:00:00Z
Note: same wall-clock digits as the Z-suffixed twin, one hour earlier in UTC

Testing contract

Expected to pass

Scenario: Parse the timestamps and convert them to UTC.
Expected result: The first point resolves to 08:00:00Z, not 09:00:00Z; a parser that ignores the offset is off by 3600 seconds throughout.

What is a .gpx file?

GPX (GPS Exchange Format) is an XML schema for GPS data, storing waypoints, routes, and tracks with coordinates, elevation, and timestamps. It is the standard interchange format for GPS devices and fitness and navigation apps. Track points capture recorded movement over time.

How to use this file

Use an example GPX file to test GPS track parsing, elevation and timestamp handling, and tools that import routes or visualize recorded activity.

How to use this file for testing

“GPX — Timestamps With a UTC Offset Instead of Z” is a deterministic Novus Examples fixture for Geospatial, Time-series data, Error handling. GeoJSON, GPX, and KML files with points, lines, polygons, and tracks — for testing map tools, route parsers, and geo importers.

Documented properties for this file: seed 20260807 · UTF-8 · LF. Compare results against paired or grouped companions on this page when present (clean↔damaged, searchable↔scanned, or format twins) so scores stay reproducible across runs.

Download the file once, keep the path stable in CI or local scripts, and treat the spec table as the contract: dimensions, seeds, field lists, and roles are intentional. Corrupt or invalid samples are labelled as such — expect parsers to fail loudly rather than silently accept them.

Geospatial fixtures publish one invented territory across formats, with the coordinate reference system and feature counts documented in specs. Convert or reproject and diff against the twin in the same group; edge-case geometries state exactly which assumption they are built to break.

Code examples

import gpxpy  # pip install gpxpy

with open("gpx-local-time-offset.gpx") as f:
    gpx = gpxpy.parse(f)
print(sum(len(t.segments) for t in gpx.tracks), "segments")