These variables control how the date is displayed (default is 'US' formatting). Go to the date() function in PHP online manual for detailed instructions on date formatting.
This format is used in the bug listing pages (eg: View Bugs). Default is 'm-d-y'.
This format is used in the view/update bug pages, bug notes, manage section, and news section. Default is 'm-d-y H:i'.
This format is used on the top of each page (current time) and the emails that are sent out. Default is 'm-d-y H:i T'.