Only in the Spring and Summer months daylight saving works for all of Australia

Only in the Spring and Summer months daylight saving works for all of Australia

daylight saving works only in the spring and summer not in winter months. I am suggesting 4 time zones in Mainland Australia and Tasmania: Winter: AWST [+8h, WA], ACWST [+9h, Eastern WA], ACST [+9.5h, NT, Western QLD, SA & Broken Hill], AEST [+10h, QLD, NSW, ACT, Vic & Tas]
Summer: AWDT [+9h, WA], ACWDT [+10h, Eastern WA], ACDT [+10.5h, NT, Western QLD, SA & Broken Hill], AEDT [+11h, QLD, NSW, ACT, Vic & Tas]