Maintain the planning calendar for the plant or for its reference plant

What causes this issue?

You have chosen an MRP lot size that requires you to specify a planning
calendar. However, no planning calendar exists for the plant specified
or for its reference plant.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Procedure for System Administrators

INCLUDE OMT4 OBJECT DOKU ID TX LANGUAGE EN
In the standard SAP system, it appears as an error message.

Error message extract from SAP system. Copyright SAP SE.