Reversing Date
When creating a new Reversing journal entry (ie you've checked the Reversing checkbox), the Reversing Date will default to the first of the month in the Reversing Period.
The Reversing Date must fall in a period after the specified Fiscal Period.
Note that should you change a Reversing Date value, the system will take measures to ensure the listed Reversing Period contains that Reversing Date and thus changing the Reversing Date value may also result in the Reversing Period changing. Likewise, changing a Reversing Period to a value that does not contain the Reversing Date will result in the Reversing Date value being changed to remain consistent with the updated Reversing Period entry.