I had this issue with my S6 as well (part of why I upgraded). But the time would be off an hour and it's caused me to be late to work before. I've not seen a valid reason or fix for this either? I'm in Indiana (DST). I don't feel that I should have to set the time manually or rely on turning airplane mode on/off to get my new phone on Americas "best" network to keep the time correct and reliable. So is this a Galaxy thing, a Verizon Network thing, or an Android 7.0 thing?