This post is targeted at people trying to set the Home Time Zone on their Galaxy S6. When traveling, the S6 tries to show the time at home on the lock screen, which could be quite useful. However, I found it quite difficult to figure out how to set the home time zone properly. I finally figured out how to do it:
Go to Settings -> Lock screen and security -> Show information -> Dual clock
Tap "Set home time zone," and choose appropriately.