Your screenshot is showing the Tasks page in PWA, so I assume this is where you want the date formatting to be applied. First of all, the Project Online application administrator cannot set the date formatting for all users on this page, so each user will need to do this him/herself. To change the date formatting on the Tasks page, click the Tasks tab at the top of expand the Tasks ribbon. In the Display section of the Tasks ribbon, click the Units pick list button, select the Date item, and then select the desired date formatting on the flyout menu. Keep in mind that PWA only offers eight date formatting options. Hope this helps.