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When I import a GPX file in QGIS (as a vector as track points) and I check the time attribute it appears to be 4 hours later than it should be. Interestingly when I take this same GPX file and use GPSBabel to convert it to a CSV file I find that the time listed in the CSV is the correct time.

So am I doing something wrong or is this a bug in QGIS.

Thanks for the help.

David

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What time zone are you living in? GPS usually works with UTC formerly known as Greenwich Mean Time. –  Andre Joost Sep 4 '13 at 8:13
    
This is in EST. But the issues is as I originally note the GPX file displays two different things. One when I use QGIS to read it and the other when I convert with GPSBabel. So perhpas QGIS automatically converts it to UTC but if so there should be a setting somewhere to deal with this. –  David Sep 11 '13 at 14:18

1 Answer 1

You can open the GPX file in a text editor.

Testing with my device, QGIS uses the same UTC format as written in the GPX file.

http://www.topografix.com/gpx_manual.asp#time

Date and time are in Univeral Coordinated Time (UTC), not local time!

The universal CSV driver of GPSbabel is able to add the local UTC offset to the data. But this value is not from the GPS unit:

http://www.gpsbabel.org/htmldoc-development/fmt_unicsv.html

Playing around with GPSBabel and the timezone declared in my Windows system settings, GPSbabel must take this offset value from the OS, unless stated in the utc option explicitely. Daylight saving time is respected, looking at the date given with the time stamp, and not the current date.

Rather strange, and undocumented...

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So if this is the situation is there a way that I can have the time attribute in QGIS that comes from a GPX file be in a local time zone or do I need to fix the GPX file somehow and then import it. –  David Sep 14 '13 at 20:41
    
QGIS uses GPSbabel to upload and download to communicate with Garmins. So it should be possible to tweak the output with Edit GPS unit, but I have not yet done that. Maybe a good idea for a plugin. –  Andre Joost Sep 15 '13 at 6:05

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