The hour hand is adjustable by a watchmaker to any orientation on the dial, but is designed to cover one of the four US timezones as home time. So mine is set to eastern time, where I live. When I travel to California, I don't reset the time at all, just look at the blue P(acific) arrow. The marketing was to the busy executive - not principally for travel, but for knowing at a glance what time it was when he made an (expensive) call to another time zone. In the mid-1950s, "multinational" for a US corporation was frequently limited to subsidiaries in London and Montreal.
G