ORACLE - NLS_DATE_LANGUAGE

The NLS_DATE_LANGUAGE parameter explicitly changes the language for abbreviations and names of days and months, and for spelled-out values of other date format elements.

NLS_DATE_LANGUAGE = language

Example :
select to_char(to_date('01-' 'JAN' '/' '2005','dd-MONTH/yyyy',
'NLS_DATE_LANGUAGE = ''ENGLISH'' ') ,
'MONTH DD, YYYY')
from dual

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