The Conversation: We Respond To Your Comments Regarding GMTs, Rainbows, and More
If I’m wearing a GMT that, like the Serica 8315, uses an independently adjustable 24-hour hand, then there is a good chance that I have the GMT hand set to UTC+0 and the main time display set to my home time. In order to change that (and ensure some level of accuracy), I would need to stop the movement, update the local time, possibly the date, and then adust the GMT hand to coordinate either to my home time or to UTC time.