I was asked to change the date format in the Zabbix front end from 'Y-m-d' (American Style) to more European style (changed it to d.m.Y). 

A user on Reddit showed me how to do it, but of course I do not know if this will have any other ramifications. 

[link Reddit Solution|

https://www.reddit.com/r/zabbix/comments/1eqdlsh/change_visible_date_format_for_clock/

]

I believe this should be part of the front end, preferably there should be a global config option, overridable by a user.