Keep Format Date to session of TOAD 12.6.0.53

In the version of TOAD 12.6.0.53

Loggeado session user does not keep the date format that has the database

locale date format customer where is installed TOAD for Oracle tool in the format as has the database and when you close the tool returns to the previous format, how to make this permanent form in the toad tool for change ALTER SESSION avoid every time I open the tool

select sysdate from dual;
This is the output
SYDATE
03/21/2016 16:30:47

ALTER SYSTEM SET NLS_DATE_FORMAT = ‘MM / DD / RRRR’

You can set the date format for Toad in Toad’s main options window.