This has been fixed now for gps-sport.net trainings exports. It will also be fixed for Run.GPS (Android) with the coming release 3.0 (early January). It is already correct for Run.GPS (iOS) :-)
Same problem, GPX export is in local time, but z is added. When you import the data in another application the time is not correct. This applies to both the (Android) application as well as the website.
GPX specification: Latitude and longitude are expressed in decimal degrees using the WGS 84 datum. Elevation is recorded in meters. Dates and times are not local time, but instead are Coordinated Universal Time (UTC) using ISO 8601 format.
This has been done intentionally this way when Run.GPS was first created (in 2007), because some programs required the Z mark but interpreted the timestamp as local time!
Yet you're right - this should be fixed. I'll put this on our TODO list.
Just checked some gpx exports from old trainings recorded in Australia, and these are also timestamped with Z suffix despite being in local Eastern Australia time which is UTC + 9 hours! So...
When I export/download a gpx OUT of gps-sport (or run.gps) the time stamp ends with Z which means 'Zulu' or UTC time. For example:
<time>2014-08-30T09:07:28.168Z</time>
But, for example, in the UK at the moment we are on UTC + 1 hour (=British Summer Time).
Hence, if I import/upload the gpx file in to other websites (Strava, Mapmyride etc), they interpret the time as UTC and hence show the time as 1 hour later, i.e. 0907 + 1 hour = 1007
My understanding is that the Z suffix signifies a standard time zone (UTC) for gpx files, but gps-sport/run.gps is not following this? Why?