If your dated are American-style, i.e. 15 July 2014 presents as 7/15/2014 instead of the Australian format of 15/7/14, then to correct the issue -

Access the controls from the top right of Google.

Select Settings

Then select Advanced Settings

Then select Language and Input Settings

Add English (Australian)

Select English (Australian)

Find English (Australian ) here

Once selected, English (Australian) will sit UNDER English

Drag & Drop English (Australian) so it sits above English (United States)

The display should look like this.

Now that English (Australian ) is correctly positioned, be sure to Select Done. Your date issue should now be resolved.