Oracle - to_date() parse of 00:00:00 - sql

Question

I am trying to format into Date from Date string by following the way,
select to_date('11/19/2019 00:00:00', 'MM/DD/YYYY HH24:MI:SS') as currentdate from dual;
The output should be,
11/19/2019 12:00:00 AM
But, I am getting the output as,
11/19/2019
When I execute following,
select to_date('11/19/2019 00:00:01', 'MM/DD/YYYY HH24:MI:SS') as currentdate from dual;
The correct output I am getting,
11/19/2019 12:00:01 AM
My nls_date_format is DD-MON-RR.
My nls_time_format is HH.MI.SSXFF AM.
I want output in the mentioned format. For all other values except than 00:00:00 is working fine.
Why 00:00:00 is not converting into the required format? Is there any way to achieve this?

Answer 1

You are getting the correct output. Only it is displayed in the default date format of your session (or database), which seems to be mm/dd/yyyy.
You control the default date format of your session with paramter nls_date_format:
alter session set nls_date_format = 'MM/DD/YYYY HH24:MI:SS';
select to_date('11/19/2019 00:00:00', 'MM/DD/YYYY HH24:MI:SS') as currentdate from dual;
Alternatively, you can use to_char() to format your date to a specific format:
select to_char(
to_date('11/19/2019 00:00:00', 'MM/DD/YYYY HH24:MI:SS'),
'MM/DD/YYYY HH24:MI:SS'
) as currentdate from dual;

Answer 2

If you want the AM format you will need this:
select to_char(to_date('19/11/2019 12:00:00 AM','dd/mm/yyyy hh:mi:ss AM'),'dd/mm/yyyy hh:mi:ss AM')
from dual;
If you run it like this:
select to_char(to_date('19/11/2019 00:00:00','dd/mm/yyyy hh:mi:ss AM'),'dd/mm/yyyy hh:mi:ss AM')
from dual;
You will get an error.
When your date format is not 24 hours(hh24) then your value for hour needs to be between 1 and 12.
Here is the DEMO
After some research I have realised what OP wants(from his comments and after he entered some more details).
Solution for OP is:
Step 1:
ALTER session SET NLS_DATE_FORMAT = 'DD-MON-RR HH.MI.SS AM';
Step 2 now this will work:
select to_date('11/19/2019 00:00:00', 'MM/DD/YYYY HH24:MI:SS') as currentdate from dual;