The time zone is not adjustable during the installation process and there are neither options in the webui. Then the user gets after installation a volumio with an incorrect time, leading to difficulties of integration with other systems.
I like the very simple installation: just copy the iso on the sd-card. Thus I would prefer to keep this simplicity and to adjust the time on the web ui.
Of course power users can simply ssh on volumio to adjust time, but I think a correct time should be easy for everyone.