Came across the problem of using the Sharepoint 2010 datetimecontrol where the date format, when selecting
from the calendar, defaults to American format when entered into the textbox.

I needed to have the date format in Australian format dd/MM/yyyy. Found the approach to take is to set the LocaleId
property to code 3081.

To find the values for the Locale Ids please refer to the following site for a list, which I found very useful.

http://msdn.microsoft.com/en-us/goglobal/bb964664.aspx

Rob