This message occurs when the Journal Date Validation option is set to either Advisory or Absolute. It is a message the lets the user know the GL Date entered is not for the Period specified.
At this time the GL Date and/or Period can be changed so the GL Date matches the Period by clicking cancel.
Note: If Journal Date Validation is set to Absolute the system will not allow the entry to post
If Journal Date Validation is set to Advisory the system will allow the entry to post