Nullarbor Time Zones

There is a confusing and peculiar time zone between Adelaide and Perth. You'll come across this timezone when you drive across the Nullarbor Plain.

The purpose of this post is to provide details about the peculiar time zone and to make you understand what is going to come ahead as you drive.

Time Zones between Adelaide and Perth

The details given in this post will be based on the below photo. Also, you can use this photo as a ready reference.

 There are 3 time zones between Adelaide and Perth. They are given below.

From the above table, you would have understood about the time zones 1 and 3. That is the time zones of South Australia and Western Australia states.

But, what about the Border time zone (ACWST)?

Well. This is a peculiar and confusing time zone.

Peculiar Border Time zone (ACWST)

ACWST (Australian Central Western Standard Time) is a peculiar timezone.

I said "peculiar" because of the following reasons.

• It is an unofficial time zone

• this time zone is based on the quarter hour

• this time zone is followed for only 350 KM along the Eyre Highway

• your smartphone won't detect this time zone automatically when you enter this area

Let me provide more details about each of the above points.

Unofficial Time zone

Border time zone (ACWST) is not an official time zone.

It is unofficial time zone agreed between the Governments of South Australia and Western Australia to be followed in some areas near the border.

Quarter Hour Time Zone

This time zone is based on the quarter hour. Not based on the half hour or the hour.

The time in this time zone is set halfway between South Australia time zone (ACST) and the Western Australia time zone (AWST). So, it is 45 minutes ahead of WA time and 45 minutes behind SA time.

Since Western Australia doesn't observe Day Light Savings (DST), this time zone (ACWST) too doesn't observe DST.

Hence, during DST, this time zone is 45 minutes ahead of WA time and an hour and 45 minutes (1:45) behind SA time.

350 KM Time Zone

This timezone is observed for only 350 KM along the Eyre Highway (A1) as shown on the map below.

Border time zone (ACWST) is observed in the following places near the border of South Australia and Western Australia.

1. Border Village Roadhouse (SA)

2. Eucla (WA)

3. Mundrabilla Roadhouse (WA)

4. Madura Roadhouse (WA)

5. Cocklebiddy Roadhouse (WA)

The number of people living in this 350 KM area is anywhere between 100 and 200. Most of them belong to the Roadhouse communities.

The remaining observers of this community are truck drivers and other travellers driving across the Nullarbor Plain.

Smartphone won't Detect Timezone

The pain is that even the latest model smartphone won't detect the Border timezone (ACWST).

If you are driving from Adelaide to Perth, when you arrive at Border Village Roadhouse (border of SA & WA), your phone will automatically change to Western Australia timezone (AWST). That is the time of Perth. Not the time of Eucla (ACWST). So, this is incorrect.

Also, If you are driving from Perth to Adelaide, when you leave Caiguna Roadhouse (WA), your phone would remain with Western Australia timezone (AWST). That is the time of Perth. Not the time of Eucla (ACWST). So, this is also incorrect.

Irrespective of your direction of travel, your smartphone won't change automatically to Border timezone (Eucla time).

So, what to do?

You have 2 options.

1. Setup Clock App on your smartphone

2. Carry a wrist watch

I opted for option #2. I relied on my watch until I crossed the border timezone area of 350 KM.

I'll provide you with the details of both options. You can choose one based on your comfort level.

1. Setup Clock App on your Smartphone

   You can use the Clock App on your phone and set up the time of the 4 places as per the screenshot shown below.

   Before you start your trip in Melbourne or Perth, set up the Clock App with times as shown in the screenshot below.

   

2. Carry a Wrist Watch

   I found this to be the easiest solution

Time Zone Change Locations

When you drive from Adelaide to Perth or Perth to Adelaide, the time zone changes in the following locations. Hence, you'll need to adjust your clock as soon as you reach these locations.

Adjust your clock in the following 2 locations.

(1) Border Village Roadhouse (border of South Australia and Western Australia)

(2) Caiguna Roadhouse (WA)

Time at Various Time Zones

How do we know the time at these time zones?

The time difference between the time zones varies depending upon summer or winter. 

Here is a simple example for better understanding.

Winter Months (April to September)

Summer Months (October to March)

As you can see, even the name of the time zones changes during summer.

• Victoria - AEST in winter has become AEDST (Australian Eastern Daylight Savings Time) in summer

• South Australia - ACST in winter has become ACDST (Australian Central Daylight Savings Time) in summer

However, no changes to WA and Border time zone as they don't observe DST.

Story Behind Border Time Zone

How was the border time zone born?

If you are curious to know about the story behind how this Border time zone was born, here is the short story.

Approximately 100 years ago, there was a Telegraph Station at Eucla.

This Telegraph station helped Western Australian Government to communicate with South Australia and other Colonies on the east coast as well as the outside world.

In this station, employees of both WA and SA worked close to each other. A big table was shared by a lot of Staff of WA and SA.

At that time, the time difference between SA and WA was an hour and 30 minutes. For example, if WA time was 9 AM, then SA time was 10:30 AM.

When the staff of SA and WA worked closely and communicated the time of messages sent or received, it caused a lot of confusion.

When a WA staff said he sent a message at 9 AM, a SA staff said he sent one at 10:30 AM while both are at the same table.

Due to this confusion, messages were sent with incorrect timings and it created a lot of problems and confusion.

To sort this issue out, both WA and SA Government agreed to follow a common time at Eucla Telegraph station. At that time, they decided to set a time halfway between WA time and SA time. So, this gave birth to a new time zone of 45 minutes.

With this new time zone, Eucla will be ahead of WA by 45 minutes and behind SA by 45 minutes. So, both WA and SA staff started to follow the Eucla time from then onwards.

Decades later, Eucla Telegraph Station was abandoned due to various reasons. However, the new time zone still survived. No Government decided to scrap that.

In reality, for people living and working near the border areas, this new time zone made sense. It would have been an injustice if they were forced to follow either SA time or WA time completely.

There is no confusion for people living and working near the border areas.

The confusion is mainly to the travellers driving across the Nullarbor. The confusion gets worst when SA follows Day Light Savings while WA doesn't.