3
As kurak_bu indicates it really depends on where (which modules) you want to change this since sometimes it is embedded in the templates or .php files.
For XOOPS in general you need to edit the /language/your_language/global.php file:
In XOOPS 2.0.16 it's in line 164-166. You'll see:
define("_DATESTRING","Y/n/j G:i:s");
define("_MEDIUMDATESTRING","Y/n/j G:i");
define("_SHORTDATESTRING","Y/n/j");
The comments following the line indicate what you can use as valid codes in these strings.
For example replace the 'Y/
n/j' in the string with 'Y/
M/j' to show the 3 letters of the Month instead of the number of the month.