This document describes how to write an ABAP routine for 0CALDAY in an InfoPackage selection to load only data for a particular date from a source system into SAP BW/BI. It provides steps to create a flat file data source, define transformations and a data transfer process, add a routine to the InfoPackage, and write ABAP code that sets the selection date to system date minus one. Running a full load using the InfoPackage will then only import data for the day before the load date.