Sailing ships move to slow for time zone differences to be noticed. It wasn't until railroads speeded up overland travel to above 60 kilometers an hour and also began to publish and adhere to strict timetables that the concept of Standard Time Zones became necessary. Prior to then, everybody set their clocks to Sun Time. Twelve noon was when the sun was directly overhead. No horse or sailing ship could move fast enough to make any shift in time noticeable to the traveler.
Source: "The Routiledge Historical Atlas of North American Railroads" has a section devoted to how the railroad industry more or less forced the United States into adopting the four standard time zones in North America.