If you fly westward at just the right speed, at just the right latitude, you can witness a perpetual sunset—a ghostly twilight that lingers, hour after hour, as you cross from one time zone to the next. For Citizen Watches, this was an intriguing thought—and soon became a compelling challenge, as the brand decided such a stunt would be a great way to show off its new Eco-Drive Satellite Wave F100 watch, which automatically adjusts to a new time zone in just three seconds. Simon Roberts was chosen to participate in the creation of the photography and to be filmed making it.