Whatever the town clock is set to. I'm surprised the author didn't mention Railway time. The standardization of time did not begin in the USA in 1883, it began

Whatever the town clock is set to. I'm surprised the author didn't mention Railway time. The standardization of time did not begin in the USA in 1883, it began in England in 1840. Before then, sundials, and later a local mean time, was used to determine local time. Railroads published almanacs with different local times, and instructions on how to reset a watch along a route to know what time it was. However, the small changes in time, or even differently timed sunsets, created problems and accidents, so to solve this they used the newly invented telegraph service along the railroad's telegraphic lines to synchronize clocks to the official time at Greenwich. This method to synchronize time then spread to India and then the United States. It was in 1880 that a law passed in Great Britain finally made the new time official across the whole country. However, as the attached article shows, neither GMT nor UTC solve everything. When humans are involved there will always be mistakes unless things are simplified for them.