What advancement primarily led to the need for timezone regulation?

The advancement that primarily led to the need for timezone regulation is long-distance communications and transportation. As the world became more interconnected through advances in travel and the establishment of global communication networks, notably in the 19th century with the expansion of railroads and telegraph systems, the limitations of local timekeeping became evident. Different regions maintained their own local times based on the position of the sun, which made scheduling across great distances complicated and often chaotic.

The introduction of standardized time zones enabled synchronization of activities across wider areas, ensuring that schedules for trains, communications, and other forms of interaction could be reliably organized. This was further supported by the need for precise coordination in increasingly complex economic and social activities that spanned multiple regions. The regulation of time into specific zones allowed societies to function more efficiently in a rapidly modernizing world, paving the way for contemporary global interactions.