Oracle 18c

By using db<>fiddle, you agree to license everything you submit by Creative Commons CC0.
select * from V$VERSION;


BANNER
BANNER_FULL
BANNER_LEGACY
CON_ID


Oracle Database 18c Express Edition Release 18.0.0.0.0 - Production
Oracle Database 18c Express Edition Release 18.0.0.0.0 - Production
Version 18.4.0.0.0
Oracle Database 18c Express Edition Release 18.0.0.0.0 - Production
0


create table date_examples( date_1 date, date_2 date, date_3 date);
-- set the same date in verious formats: ISO Standare, Declared Standard, a strange format
insert into date_examples( date_1, date_2, date_3) 
  select date '2021-02-18'                   -- standard iso format 
       , to_date('18-Feb-21')                -- default see alter session 
       , to_date('18 2021 02', 'dd yyyy mm') -- specified
  from dual;
1 rows affected

-- what are the verious dates without specifying how   
select * from date_examples;


DATE_1
DATE_2
DATE_3


18-FEB-21
18-FEB-21
18-FEB-21


  select to_char(date_1, 'mm/dd/yyyy')     "Std mm/dd/yyyy"
       , to_char(date_2, 'Month yyyy')     "Month Year"    
       , to_char(date_3,'FMDay dd Month, yyyy')  "Day Date Month" 
  from date_examples;


Std mm/dd/yyyy
Month Year
Day Date Month


02/18/2021
February  2021
Thursday 18 February, 2021


-- take a peek at the inside. 
select dump(date_1), dump(date_2), dump(date_3) 
  from date_examples;


DUMP(DATE_1)
DUMP(DATE_2)
DUMP(DATE_3)


Typ=12 Len=7: 120,121,2,18,1,1,1
Typ=12 Len=7: 120,121,2,18,1,1,1
Typ=12 Len=7: 120,121,2,18,1,1,1