3812082 - Why do I see timing difference in "Expense Workflow" in "Process Reports" and Cognos reporting?

I have created a Custom Report to see the Workflow Cycle, however few of the reports show the different date and time for Step Action Date/Time column. I would like to know why is this difference between Expense system and Reporting

I have noticed that there is a timing difference for sent for payment date in one of my Cognos Report. , KBA , CON-CA-ADM , Administration , Problem