ORA-01861 : WHILE USING LTRIM(RTRIM(VAR_NAME));

[Oracledba8]

Here is the Description of the Error

ORA-01861 literal does not match format string

Cause: Literals in the input must be the same length as literals in the format string (with the exception of leading white space). If the "FX" modifier has been toggled on, the literal must match exactly, with no extra white space.

Action: Correct the format string to match the literal.