Australia uses three main time zones: Australian Eastern Standard Time, Australian Central Standard Time and Australian Western Standard Time.
Road sign near Broken Hill
A time zone is an area which observes a uniform standard time for legal, commercial and social purposes. Time zones tend to follow the boundaries between countries and their subdivisions instead of strictly following longitude, because it is convenient for areas in frequent communication to keep the same time.
Plaque commemorating the Railway General Time Convention of 1883 in North America
The control panel of the Time Zone Clock in front of Coventry Transport Museum