Syncing the Time with Garmin Connect

I don't know why you would want to. Setting time via GPS will be the most accurate time you can get. 

I would want it for the same reason I bought the watch in the first place - convenience.

Well lucky for you then because Garmin does infact sync time via Bluetooth

support.garmin.com/.../

This doesn't apply to Instinct 2 - it only syncs with GPS. That said Fenix seems to be able to sync via BT, hence Garmin could enable this for Instinct 2 if they wanted to.

This is incorrect.

Garmin does indeed update via Bluetooth. To verify I set my time to manually a wrong time. Then set back to auto. Time updated with sync to Garmin connect app. If you are having problems with your time I would verify your time mode is set to auto and if you still don't update try restarting.

I had it set to Auto. But I tried your method now - going manual - changing to random time - going to auto and syncing - and you're right it does sync... but it's behind the phone clock (hence why I assumed it's not syncing). We're talking roughly 1-2 sec behind the phone clock here. Funny enough when I acquire GPS sync it's about 1 second ahead of the phone clock - which matches my atomic clocks. 

OK, the difference is not massive but it's mind boggling that it struggles to sync perfectly.

In that case Garmin is most likely not using your actual phones times. More likely pulling the time from somewhere online based on your location. That time happens to be a few seconds different from what your local cell tower is reporting. 

I would go with GPS if I was you. They are definitely going to be the most accurate

9098866 said:

In that case Garmin is most likely not using your actual phones times. More likely pulling the time from somewhere online based on your location.

Well yeah, it's doing something unusual that only Garmin knows what that is. It's my first Garmin watch but not a first Garmin device - I got used to things not always making sense.

As for using GPS, as per what I mentioned earlier - it's not perfect either. My atomic watches match my phone/computers/tablets which match the online time which match local clocks. Neither of which match Garmin, be it synced via GPS or BT. Do you see a pattern here? No point trying to find excuses on behalf of Garmin there. Unless you work for them - in which case can you forward my post to someone who can look into this?

I do not work for Garmin. But every GPS satellite actually contains multiple atomic clocks that are accurate within 3 ns. So, I find it very surprising you're finding this time inaccurate. It's possible the watches are miscalculating the time differential for the time the satelite transmits and the time it arrives. But this would also mess with location accuracy which I have found to be very accurate. 

I just checked my Instinct 2 with the accurate time server at https://time.is/, and it is exactly the same, to the second. Which is not surprising. You can barely get more accurate time than from GPS.