Question: what are the four time zones in united states
Answer: Atlantic Time Zone; UTC-4; AST; Eastern Time Zone; EDT; EST; Eastern Standard Time; North American Eastern Time Zone; Mountain Time Zone; MT; Mountain Standard Time; Mountain Daylight Time; MDT; MST; Pacific Time Zone; PST (UTC-8); Pacific Standard Time Zone; PDT (UTC-7); PT; Pacific Daylight Time; Central Time Zone; Central Daylight Time; Central Standard Time Zone; CDT; CST; North American Central Time Zone; Central Standard Time