<P> Only the full - time zone names listed below are official; abbreviations are by common use conventions, and duplicated elsewhere in the world for different time zones . </P> <P> The United States uses nine standard time zones . As defined by US law they are: </P> <Ol> <Li> The Atlantic standard time zone </Li> <Li> The Eastern standard time zone </Li> <Li> The Central standard time zone </Li> <Li> The Mountain standard time zone </Li> <Li> The Pacific standard time zone </Li> <Li> The Alaska standard time zone </Li> <Li> The Hawaii--Aleutian standard time zone </Li> <Li> The Samoa standard time zone </Li> <Li> The Chamorro standard time zone </Li> </Ol> <Li> The Atlantic standard time zone </Li>

What are the time zones of the usa