set default timezone, date first day and date format medium via drush
There is no specific command to set default value. You need to set those variables using drushcommands.

For Drupal 7 version you can use below commands.


To set default timezone you can use


drush vset date_default_timezone 'Europe/London' -y


To set date first day you can use


drush vset date_first_day 1 -y

I hope this helps..  :)