Calling Australian Taxation Office PTAX Enquires Line ... Time-Of-Day

I have a card from ATO titled, "Contacting the ATO".
In this card, Personal tax enquiries number is listed as 13 28 61, and, the timings are Monday to Friday, 8.00am to 6.00pm.

The time in Sydney was 7.25pm. I called 13 28 61, expecting to hear an out of business hours announcement. To my surprise, there was an agent available !

How was it that while the published time is until 6.00pm, an agent was available at 7.25pm ?

It was possible because the call was routed to Western Australia, where the time was 4.25pm !

Good thinking by ATO ... instead of checking time-of-day of the zone from where call originates, ATO first determines whether there is any zone where time-of-day is within 8 - 6 business hours, and then routes the call to that zone, or, it might just be checking whether there was an agent logged in countrywide.