OPEN DAY - The open day refers to the date for which the user is processing transactions.  Once a transaction is made the date is opened.  Once the Close Day option is processed the day is closed.  Days can be closed and re-opened only if processed on the same day.  For example, you can close 1/2/2002 and re-open 1/2/2002 as long as there are no other records following that date in the Summary File.  However, if you close 1/2/2002 and also close 1/3/2002, you cannot reopen 1/2/2002 again.