How To Fix CN828 - Start of time interval must not be negative

SAP Error Message - Details

• Message type: E = Error

• Message class: CN - Meldungen für Netzpläne

• Message number: 828

• Message text: Start of time interval must not be negative

What causes this issue?

You have entered a value for the time interval that is <ZH>before</>
the start date of the activity. This is not allowed.

System Response

INCLUDE 'NA_ALLG_NOVERARBEITUNG' OBJECT DOKU ID TX

How to fix this error?

Enter a different time interval for the start of the activity element.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message CN828 - Start of time interval must not be negative ?

  The SAP error message CN828 "Start of time interval must not be negative" typically occurs in the context of project management or controlling modules, particularly when dealing with time intervals for activities, costs, or scheduling. This error indicates that a time interval has been defined incorrectly, where the start time is set to a negative value, which is not permissible.
  Cause:
  
  Incorrect Data Entry: The most common cause is that a user has entered a negative value for the start time of a project activity or cost element.
  Date Calculation Errors: If there are calculations or formulas that derive the start time from other values, an error in those calculations could lead to a negative start time.
  Configuration Issues: There may be issues in the configuration of the project or controlling settings that lead to incorrect time interval definitions.
  
  Solution:
  
  Check Input Values: Review the input values for the time intervals in the relevant transaction or screen. Ensure that the start time is set to a valid, non-negative value.
  Review Calculations: If the start time is derived from other fields, check the logic and calculations to ensure they do not result in negative values.
  Adjust Project Settings: If the error is related to project settings, review the project definition and ensure that all time-related fields are correctly configured.
  Consult Documentation: Refer to SAP documentation or help resources for specific guidance on the transaction or module you are working with.
  Contact Support: If the issue persists and you cannot identify the cause, consider reaching out to your SAP support team or consulting with an SAP expert.
  
  Related Information:
  
  Transaction Codes: The error may occur in various transaction codes related to project management (e.g., CJ20N for project planning, CJ02 for project change).
  SAP Notes: Check SAP Notes for any known issues or patches related to this error message.
  User Roles: Ensure that the user has the appropriate permissions to make changes to project settings, as restrictions may lead to unexpected behavior.
  Testing: After making changes, test the input again to ensure that the error does not reoccur.
  
  By following these steps, you should be able to resolve the CN828 error and ensure that your time intervals are correctly defined in SAP.