Daylight Saving Time (DST) is the practice of advancing clocks one hour during the warmer months of the year to make better use of natural daylight. In Australia, DST is observed in New South Wales, Victoria, South Australia, Tasmania, the Australian Capital Territory, and Norfolk Island. However, each state and territory of Australia determines whether or not to use DST. Queensland, the Northern Territory, Western Australia, Christmas Island, and the Cocos (Keeling) Islands do not observe DST.

DST begins at 2 am on the first Sunday in October, when clocks are set forward one hour, and ends at 2 am (which is 3 am DST) on the first Sunday in April, when clocks are set back one hour. During DST, there is more usable daylight in the evening, which provides more time for outdoor activities and reduces energy consumption.

It is worth noting that the implementation of DST in Australia is not without controversy. Some people argue that it causes confusion, disrupts sleep patterns, and has negative effects on health and productivity. Others believe that it provides more time for leisure activities and reduces traffic accidents.