Okay, got it to work for me so far.

It seems there is a problem with running under php-fpm, adding the timezone to php.ini seems not to work.

I configured the php-fpm config file for that webspace with:

php_value[date.timezone] = "Europe/Vienna"

Then the time zone error went away.

Additionally I switched to Mysql and created the missing table tags as suggested here in the forum.

Maybe the information helps somebody else.

Thoma