how to set Default time zone and date format
You can set default timezone and whether user should be able to edit default timezone settings or not.

Go to Regional and language settings:

http://yousite.com/admin/config/regional/settings

And uncheck : Users may set their own time zone.

On same page other settings also available. See :  



To add any new format you can add from here :

http://yousite.com/admin/config/regional/date-time