Factory calendar &1 from plant &2 is not available

What causes this issue?

Factory calendar &V1& does not exist in the system.

System Response

The system rejects the date you have entered because it cannot check it
against the calendar.

How to fix this error?

Either create calendar &V1&, or assign another valid calendar to plant
&V2&.

Procedure for System Administrators

Factory calendar <(>&<)>1 for plant <(>&<)>2 does not exist.

Error message extract from SAP system. Copyright SAP SE.