The first ever time zone was put in place by British rail companies on December 1st 1847 as a solution to the chaos created by each village or town running on solar time, with its town clock showing midday when the sun was at its zenith. Not surprisingly, given its east-west extent, Australia has three time zones, with east coast cities being two hours ahead of Perth on the west coast (at least as I write this). More bizarrely, the middle time zone comprising Northern Territory and South Australia is not centrally placed timewise, but an hour and a half ahead of Perth, and half an hour behind Cairns. This set me wondering which of the places that I'm going to visit are closest to their solar time.
My home town is (as I write this) an hour and 37 minues ahead of solar time, and Kuala Lumpur's nearly as far out, being an hour and 7 minutes ahead. All the places in Australia that I'm going to visit are currently closer to solar time: Perth (17 minutes ahead), Darwin (35 minutes ahead), Alice Springs (22 minutes ahead), Cairns (13 minues ahead) and Melbourne (20 minutes ahead, but will be an hour and 20 minutes ahead by the time I get there because of daylight savings time [DST, or 'summer time']). Only the south-eastern Australian states have DST (the unhatched ones on the map above), so my domestic flights in Australia will involve time changes of +1.5, 0, + 0.5 and +1 hours, respectively.
One oddity is that because DST involves the clocks going forward in spring in both hemispheres, the clocks go in opposite directions in the two hemispheres in March and in October. If I was coming home a week or so later, the time change would be 6 hours on the outer trip and 10 on the way back - half from crossing the continent, and half from the accumulated effects of opposite DST changes.
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