Incorrect local date - Australian format

Also from Aus.  There are a few ways to handle this and i've had some headaches with this too.  I work on some US VMs as well which throws additional spanners in the works so I certainly feel your pain.

The very first thing to you want to check is whether your dates are being stored correctly and just shown as US format, or whether they are being stored incorrectly but shown in the correct format.

For example  if your source system gave you 08.10.2018.  Did it record correctly as the 8th of October and then display as 10/08/2018, or did it store it as 10th August and then show it as 10/08/2018?  The easiest way to test that is to import the data set and then use the formatting tools to show the date in the 10-Oct-2018 type format.

First Power Query formula worth trying is Date.FromText( )  This usually does a pretty good job, especially if you format the string dates into the YYYY-MM-DD format.

You could also attempt a 'Split column by delimiter' to create 3 columns giving you the Day, Month and Year.  You could then create the new date formatted column using Date.FromtText([YEAR] & "-" & [Month] & "-" & [Day]) where the columns i mentioned are your 3 split out columns.