By default Joomla shows the date and time in the article. While this is, for the most part, a useful feature there are plenty of times I'd rather not have the time appear. Who needs to know that I was up at 4 AM working on an article? You can globally turn off the date display in the Article Manager in Parameters, it's pretty limited. You can only turn it on or off.
The controls for the time and date format can be found in the following folder: root/language/en-GB. Look for the en-GB.ini, and open it in a test editor.
The image below illustrates that you can edit the following line in the file: DATE_FORMAT_LC2=%A, %d %B %Y %H:%M.
They are in order of appearance. To remove the time, delete %H :%M.
