Error: Date is in this Yr but Prior Mth

Following error is showing at the time of sales update, somebody can help us?

Subject : Error: Date is in this Yr but Prior Mth

CAUSE . . . . The date being edited is in the current year but in a prior

month.

RESOLUTION. . This is an error if in the General Accounting Constants you

do not allow PBCO (posted before cutoff) entries. Change the

date or change the General Accounting Constants to allow PBCO

entries.

thanks