SAP Message TU088 - With annual payer one combination in 'Allowable date' must read 12;1

Diagnosis
You have selected the Annual payer field. To ensure that asuitable annual budget billing amount due date is generated, you mustenter the combination 12/1 in the Allowable date field.

Procedure
If you wish to use the Annual payer field, enter the combination12/1 in the Allowable date field.