Using Retained Earnings

[Lars Jensen]

Hi,

As a newbie to gnucash, I have some questions about transferring funds 
to Equity:Retained Earnings at the end of an accounting period :

(1) Is there some place in gnucash where one defines the duration of an 
accounting period?

(2) Is this supposed to be done automatically by gnucash, or is it 
something I do manually? If I do this manually, how exactly is this done?

Thanks for any help with this,
Lars.