It checks for the systemglobals.properties / jforum-custom.properties.
The key within that properties is specifed by ConfigKeys.DATE_TIME_FORMAT. I assume that the
string should contain something along with'date' or 'time' in it. You can check the systemglobals.properties if you find the value.
I suggest to not simple replace the value in the properties then, but rather add that key/value pair to the jforum-custom.properties. This file is always checked first, and overwrites the default values within the systemglobals.properties
[originally posted on jforum.net by Sid]