how do i change the default date format in pages 09'

Hello:

I am using Pages 09'. and I want to change the default date format when I insert date in a document.

I understand how to change the date format when I insert, and that is not the issue.

Currently when I insert the date in a document is is formatted week day/month/date/year. I want to change the format to month/date/year.

Any help is appreciated please.

Thank you.