: All standard times are calculated as an offset from Coordinated Universal Time (UTC) , allowing different countries to coordinate across the globe. Standard vs. Daylight Saving Time

: It prevents the chaos of having different times in cities only a few miles apart, which was a major issue for railway schedules in the 19th century.

Standard time is the synchronization of all clocks within a specific geographical region to a single uniform time. Instead of following "solar time"—which varies by about four minutes for every degree of longitude—standard time creates consistency for travel, commerce, and communication. Why Standard Time Matters