How can I setup, defalt time zone for all? because I you say all user have to follow the steps to get correct time.
By default, roundcube uses
auto that should take the time zone from server. If you want to change it, edit file
/etc/roundcube/config.inc.php and add the following option:
$config['timezone'] = 'auto';
auto by the time zone you want to use, example using time zone for Spain.
$config['timezone'] = 'Europe/Madrid';
To get your time zone, visit this link: