Ya, it's the clock alright, only, that's not the issue (being slightly inaccurate).
First off, I updated the GoPro firmware. Didn't make a diff.
I've run several test sequences, here's what I see:
I got a proper bike mount for my phone, so I could see it as the sequence captures (before, I had the phone in my pocket). I can see on the screen as I ride that the GPS is green, the map is tracking, and it is dropping little green dots along my path as I ride. That seems fine.
BUT, when I hit stop and let it transfer the photos to the app, the photos always come in "backwards", as in, in reverse order from the order that they would show if I shot from the app itself. The app itself shows the first photo taken as the first item in the list (top-left corner of the list of images). When transferring from the GoPro, they come in with that photo, the top-left one, being the last photo taken. They are backwards. If I view them on the GoPro, using its sequence player of multi-sequence photos, they run in the right order.
But here is what the time thing comes in. In the app, it shows a big banner over the photo sequence (in the sequence list) that says the date and time the sequence was started. On my GoPro-shot sequences, they show 6 hours earlier from when I shot them. For example, I just shot a test sequence walking through my backward, at 4:30 PM local time. The sequence shows up in the list as being from "Today, 10:30 AM". 6 hours ago. 6 hours also just happens to be the time difference between where I live and UTC. But, UTC is 6 hours AHEAD from me. At the time I shot the photos, it would have been 22:30 UTC. I looked at the EXIF data on the GoPro pictures, and I don't see anything in there that indicates what time zone they were shot in. I did try to set the time on my GoPro to UTC before shooting, but the software ever so helpfully syncs the time on the camera to the time on the phone, which itself is being pulled in from the phone company, so, it is "always right" for where I am.
Here's what I think is happening: The app thinks it needs to do some time math, because of the difference in time between where I am and UTC. It doesn't need to, but it does anyway, subtracting 6 hours from the time the photo was shot, making it 6 hours too early, because the photo is already flagged with local time, not UTC. I'm not sure how that makes the photos go backwards, but, well, there it is. But it might also be what is screwing up the GPS info. All photos in any sequence I take with the GoPro always all have the starting point, the first photo placement, as the GPS coordinates for ALL photos in the sequence. Since GPS and time are so interconnected, there's probably also something going on there.