Date and Data Transactions
SAP systems have very high data integrity. To keep this data integrity the SAP system maintains and manages all data records, changes, system audit trails, etc., by date. For this reason, when a SAP BAPI is used to retrieve or edit data, the system requires that a date parameter be passed into the BAPI to validate the transaction.
The advantage of this feature (from the SAP perspective) is that the system can be "rolled back" at any time to a specific point in its history based on the transactional date presented. This feature also enables queries to be performed when a transactional date reference is provided.
The partial image provided below displays the date parameter for a randomly selected BAPI. The date parameter is identified by the 0 [numerical 0], included in the name.