The government website of Australia states the time zone names for Australia are Australian Eastern Standard Time (AEST), ...
I'm afraid it's not that simple. Different websites operated by the government of Australia use different names and abbreviations. The Bureau of Meteorology often uses EST/CST/WST and EDT/CDT; see, for example, <http://www.bom.gov.au/satellite/about_satpix.shtml>. And the Australian Transport Safety Bureau often uses EST/CST/WST and ESuT/CSuT; see, for example, <http://www.atsb.gov.au/media/690841/ar-2009-016(2).pdf>. The tz database's philosophy has generally tried to record what people typically do with their clocks and their abbreviations. If one government agency says that it's AEST/AEDT, that's a good piece of evidence; but if other agencies disagree, that's evidence that there's not a solid consensus within the government what the abbreviations are or should be. The most amusing thing about <http://australia.gov.au/about-australia/our-country/time>, the web page that Richard Stanway quoted, was this little message at its bottom: "All times shown are Sydney, Australia Time" In other words, the Australian government doesn't follow its own advice on time zone names and abbreviations, even on the government page that talks about time zone names! They just say the equivalent of "TZ=Australia/Sydney"!