& days with double public holiday in generation period

What causes this issue?

There is more than one public holiday per day on several days within
the generation perod. You must decide which public holiday class should
apply in this case.

System Response

The System requires that you insert the months individually.

How to fix this error?

Use the 'Create all' function instead of the 'Create' function.
In this way, you automatically access the days on which several public
holidays are celebrated. The public holday class which applies for these
days is indicated with a star.

Error message extract from SAP system. Copyright SAP SE.