The prime time zone for Eastern Standard Time (EST) is UTC-5. This time zone is primarily observed in the eastern part of the United States, including major cities like New York, Atlanta, and Washington, D.C. During Daylight Saving Time, which typically runs from spring to fall, Eastern Daylight Time (EDT) is observed, shifting the time to UTC-4. EST is significant for travel schedules, business operations, and broadcasting times, aligning daily activities with the circadian rhythms of the population in this region. Awareness of EST is essential for scheduling and coordination in various sectors.