Why is time offset 45 minutes at the WA/SA Border?

For the 350 kilometres of Eyre Highway between Caiguna and Border Village Australian Central Western Standard Time is used.

This is UTC1 +8.45 hours – 45 minutes ahead of Perth and 45 minutes behind Adelaide. Perth is UTC +8 hours and Adelaide is UTC+9.30 hours.

It is reputed that this came about in the time of telegraphic communications. The telegraph line between Western Australia and South Australia opened in December 1877. Prior to the Federation of Australia (1901) colonies were responsible for their own communications and at Eucla (virtually on the WA/SA border) telegrams from, say, Western Australia were handed to South Australian operators sitting on the opposite side of the table for re-transmission. A telegram from WA that was time stamped 10:00 a.m. would be re-transmitted with the SA time of 11:30 a.m. This caused a lot of confusion that was resolved by the WA and SA Government agreeing to follow a common time at Eucla Telegraph Station midway between the two states’ official time zones.

This gave rise to Australian Central Western Standard Time. It does not extend into South Australia. This use of this quirky time zone was not repealed with the demise of the telegraph.

  1.  UTC replaced Greenwich Mean Time (GMT) in 1972.