Prior to railroads, local time was determined by making it Noon when the sun was directly overhead. Time zones became necessary when railways spread in order to

Prior to railroads, local time was determined by making it Noon when the sun was directly overhead. Time zones became necessary when railways spread in order to be able to catch your train. Airplanes use Zulu Time because they can fly fast enough to make it a confusing mess to do anything else. This is the same problem the railways had, but the next order of magnitude up. We already have and use Zulu Time for airplanes. There is no compelling argument here for making that universal. Local time zones still make sense in terms of setting schedules for local services, jobs, etc. The fact that I can talk to people all over the world isn't a compelling reason to move to a singular Earth Time.