speedup some Delphi+SQL code

I have a Firebird stored procedure (OUTLETHRSDONE) that is used by a Delphi application. This SP calls other SPs which call other SPs etc: rather complex. The procedure is used to get the shifts (and similar information) of all employees in a date range. I want to change the whole way I retrieve data from the database. Instead of using the SP to directly get processed/ready-to-use data from the database, I plan to get raw data and process it in memory using Delphi code. See the attached specs