I have a Client using PowerPoint in Microsoft Office 2008 (12.0.0) on a Mac.
If she wants to insert the date from "insert" it only allow her to insert it like MM/dd/yyyy (that is US format).
If she opens a document where "current" date was inserted and set to automaticly update it also has det "month first" format.
I am unable to locate any settings in Offce where the date format can be changed.
In Systems settings for the Mac OS X 10.7.5. everything seems OK here the format is dd/mm/yyyy
On windows I would simply change the Regional settings in the control panel, which would change the format i Office, but it seems it is different on a mac.