Today about 70 countries use Daylight Saving Time (DST). Daylight Saving was first introduced during
World War I in Australia. During the world wars, DST was used for the late summers beginning January
1917 and 1942, and the full summers beginning September 1942 and 1943.
     In 1967, Tasmania experienced a drought (干旱). The State Government introduced one hour of daylight
saving that summer as a way of saving power and water. Tasmanians liked the idea of daylight saving and the
Tasmanian Government has declared daylight saving each summer since 1968. Persuaded by the Tasmanian
Government, all states except two passed a law in 1971, for a test use of daylight saving. In 1972, New South
Wales, South Australia and Victoria joined Tasmania for regular daylight saving, but Queensland did not do so
until 1989.
     Tasmania, Queensland and South Australia have had irregular plans, often changing their dates due to politics
or festivals (节日). For example, in 1992, Tasmania extended (延长) daylight saving by an extra month while
South Australia began extending daylight saving by two weeks for the Adelaide Festival. Special daylight saving
plans were made during the Sydney 2000 Olympic Games.
     The differences in daylight saving in Australia continue to cause serious problems in transport and many
other social activities. It also reduces the number of hours in the working day that are common to all centers
in the country. In particular, time differences along the east coast cause major differences, especially for the
broadcasters of national radio and television.