Learn the cause and how to unravel the ORA-01820 error message in Oracle.
When you come across an ORA-01820 error, the following error message will appear:
ORA-01820: layout code can’t appear in date enter structure
You tried to enter a date value, however you used a date format that is now not valid.
The option(s) to resolve this Oracle error are:
Check the date formats diagnosed through the TO_DATE function. Correct the format and retry.