Final answer:
Coordinated Universal Time (UTC) is the standard reference time used worldwide, based on the local time at 0 degrees longitude in Greenwich, England. It facilitates a unified time system for global operations, with 24 time zones correlating to the Earth's rotation.
Step-by-step explanation:
The standard reference time for all points on Earth is Coordinated Universal Time (UTC), formerly known as Greenwich Mean Time (GMT). This system was agreed upon internationally to facilitate various global operations.
UTC is based on the local time at the prime meridian, 0 degrees longitude, which runs through Greenwich, England. Due to the Earth's rotation at 15 degrees per hour, we have a system of 24 time zones, each covering 15 degrees of longitude, paralleling the 24-hour cycle.
For example, Eastern Standard Time (EST) is 5 hours behind UTC as it is located approximately 75 degrees west of Greenwich, England. Globally, while most countries use these standardized time zones, some like India and China have unique adaptations, with India using a half-zone difference of 5.5 hours ahead of UTC, and China using a single time zone across the entire country.