In case you get the following warning:

warning: strtotime(): It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Europe/Berlin' for 'CEST/2.0/DST' instead
 
In
/etc/php.ini, line 947 please put:
date.timezone = "Europe/Oslo"
And restart the webserver.