I'm having and issue with SQL Developer Version 3.2.20.09 where my settings in the NLS Date and Time preferences are not being used for the nls_session_parameters.
I've changed the default Date Format to RRRR-MM-DD HH24:MM:SS in the preferences, but when I start new sessions the format remains the default set of DD-MON-RR as verified when I run
If I run
alter session set NLS_DATE_FORMAT = 'RRRR-MM-DD HH24:MM:SS'
I can get the information to display the way I want it to, but it resets every time I start a new session.