SharePoint Date And Time Column

This is probably a very simple problem to correct but I have a Date Time column in SharePoint. However when the user enters t开发者_运维问答he date it only accepts dates in American format. I need to change this to use UK format. How do I do this?

I had to configure the regional settings in SharePoint, found this info here:

http://www.informationworker.co.za/blogs/BramsOnSharePoint/Lists/Posts/Post.aspx?ID=2

However if you have sub-sites already created you have to manually update the regional settings for each sub-site.