How To Fix W8198 - Value of type & is used for defining date (type &)

W8198 - Overview

• Message type: E = Error

• Message class: W8 - Workflow: Expressions, data flow

• Message number: 198

• Message text: Value of type & is used for defining date (type &)

What causes this issue?

You are trying to assign an element of data type &v1& to an element of
data type &v2&.

System Response

In cases concerning assignments, a conversion is executed at runtime
involving &v1& in &v2&, under the following rules:
N -> D,,First the conversion N -> C takes place and then C -> D.
N -> C,,The numerical field is treated like a text field,
,,,,,,leading zeros are retained.
C -> D,, the text field should contain an 8-digit date in the form
,,,,,,YYYYMMDD.

How to fix this error?

You should ensure that only data type &V2& can be included when
calculating difference days. The necessary type conversions (MOVE) are
executed internally automatically before the arithmetic operation. For
reasons of efficiency, however, only operands of the same numeric data
type should occur within one arithmetic expression, if possible (up to
the operands for STRLEN): in such cases, no conversion is required and
special internal optimization can be carried out.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.

W8198 - Details

• Certainly! Here's a detailed explanation for the SAP error message:
  
  SAP Error Message:
  W8198: Value of type & is used for defining date (type &)
  
  
  Cause:
  This warning message occurs when a value of a certain data type is used to define or assign a date variable, but the data type of the value does not match the expected date type. In other words, the system detects that a value of one data type (e.g., character or numeric) is being assigned or compared to a variable that is defined as a date type (DATS).
  For example, if you try to assign a character string or a numeric value directly to a date field without proper conversion, this warning will be triggered.
  
  Explanation:
  
  The message placeholders & are replaced by the actual data types involved.
  The system expects a date type (DATS) but finds a different type (e.g., CHAR, NUMC, or I).
  This is a warning (not an error), so