Explain why countries like australia and america have more than one standard time that is used

The different standard times are known as time zones. Time zones are useful because  they can allow people to be active during the day and sleep during the night. If people spent hours with sunlight sleeping and worked in the dark, they would likely suffer health problems.

Big countries such as Australia and the United States have many time zones so that people can work and sleep in the time that is adjusted to the hours with sunlight in their specific location.