Are you located near the delimitation of two different time zones? Or do you use a different time zone on your phone, than is officially used in your region? The device syncs the time each time you turn it on, with GPS satellites, and each time you sync with your phone. So if the GPS and the phone time differ, the time on the device will change each time accordingly.
I am in the UK , when the clocks went back in October my Garmin stayed on British summertime, when I sync it to my phone the time of day on the Garmin does not change , I was wondering if there was a way I could manually correct the time of day
