Every Joomla page can display created and modified datetime of the article. Default format is defined by currently used language pack. If you want to change datetime format then you have two options:

1. Change currently used language pack. You can download and install Croatian language pack from here
2. Manually edit en-GB.ini file inside /language/en-GB directory if en-GB is default lang pack. Change entry for DATE_FORMAT_LC2, e.g to set datetime format to day.month.year use DATE_FORMAT_LC2=%d.%m.%Y For details on how to format date see php manuals as this is php format string.

See list of all Joomla mini how to's from this site