Date parameter is not getting incremented when i schedule a request set

 Hi,

         I created a request set to import invoices in payables.This includes loader program ,validation program and payable open interface import.I used the date as a batch name in payable open interface import program.when I scheduled this request set,i checked the increment date parameter in schedule window to increment the date which is used for batch name.This is not happening as expected,it is just using same date.Can any one please let me know how to increment this date?