ABSTRACT
The ultimate goal of the NTP infrastructure is to synchronize clocks of the network to a common timescale, but it may or may not be the case that the timescale is synchronized by international agreement. For example, in the early 20th century, the most accurate clocks in the land were kept by railroaders. While it took 2 days to cross the country by passenger rail, it was crucial when meeting at a siding that train engineers had the right time. It did not matter if railroad time was tied to the Sun, Moon, or stars, just that the railroaders’ pocketwatches kept the same time.
