The time difference varies by season. During standard time (November to March), both cities show the same time. During daylight saving time (March to November), Phoenix is 1 hour behind Salt Lake City since Arizona does not observe DST.
Salt Lake City uses Mountain Time and observes daylight saving time. Phoenix uses Mountain Standard Time (MST/UTC-7) year-round, as Arizona is one of the few US states that does not observe DST (except the Navajo Nation).
Business hours align well year-round. During standard time, no conversion is needed. During DST, remember Phoenix is 1 hour behind - a 10:00 AM meeting in Salt Lake City means 9:00 AM in Phoenix.
Many businesses operate between these southwestern cities. The variable time difference catches some people off guard, so always verify the current date when scheduling important meetings.