We have a Z function module that calls
CALL FUNCTION 'BAPI_RESERVATION_CREATE'
to create a reservation per Material, Quantity, SoldTo, etc.
Some time ago, someone modified table RESB for the reservation with a custom column called ZCRTIME, which is supposed to hold the time stamp that the reservation gets created. This will be used later in comparing how old the reservation is. That person never added the functionality to actually UPDATE the new column, however.
The custom field has been added to RESB, but in what way can I add the timestamp to when RESB gets updated? Is this a function and perhaps userexit in MB21?