[XeTeX] Setting default date format for biblatex: babel or polyglossia

[R (Chandra) Chandrasekhar]

Dear Folks,

I have a question involving biblatex and babel/polyglossia that I have 
posted here simply because the document is being processed by xelatex. 
If another forum would be more appropriate, kindly re-direct me to it.

I am processing a document that uses biblatex for bibliography 
processing before being compiled by xelatex.

I want to customize bibliographic date fields like \urldateshort to use 
the format dd/mm/yyyy which is available when I declare this in the 
preamble:

\usepackage[australian]{babel}

However, if I replaced babel with polyglossia above, the result is not 
the same, but rather the default (american?) format.

I have two questions regarding this:

1. I think there are more elegant ways of accomplishing this by 
declaring Australian localized formatting in the biblatex.cfg file. Does 
this entail copying the definitions from the file australian.lbx into 
biblatex.cfg, or is there a neater way to do this?

2. If (1) is not available, is there any simple way, other than 
declaring the language for babel, as above, to achieve easy 
customization of date fields? I have scanned the comprehensive biblatex 
manual a couple of times, but not been able to get the answer.

Thanks.

Chandra