Run recorded on Garmin 35, and synced to Strava from Garmin Connect. I ran non-stop with no pauses of any kind. I started the watch the moment I started to run and I stopped the watch the moment I stopped. (But I may have 'saved' a few seconds after stopping IYSWIM.)
Garmin Connect:
Elapsed time: 34:27
Moving time: 34:27
Strava:
Elapsed time: 35.32
Moving time: 33.37
Pace data is not identical between the two.
Strava appears to have added time to the Elapsed time, and generally makes no sense. How can my Elapsed time possibly be longer than the Garmin thinks the watch itself was timing?
On the face of it either Strava is completely mangling the timing or Connect is feeding Strava duff data for competitive advantage...
Download the GPX file from each and open them in a text editor. You'll be able to see all the timestamps. Might give you clue.