The report seems to match the application so the the DWH data should be up to date.
For 14.4 the
Late Tasks and Milestones Portlet
describes Days late as follows
Days Late
Displays the number of days late considering the following:
- Whether or not a baseline exists
- Task status
If a baseline exists, then days late is calculated as task finish date minus baseline finish date. A positive number indicates that the task is late according to the baseline. A negative number indicates that it is early according to the baseline.
If a baseline exists and the task finish date is the same as the baseline finish date, then the task is considered late if it is not completed and it was due before today’s date. In this case, days late is calculated as today’s date minus task finish date.
If there is no baseline, then days late is calculated if the task is not completed and it was due before today’s date. In this case, days late is calculated as today’s date minus task finish date.
that explains at least one day if the report was run 12/05/16 and maybe more depending on how exactly the date arithmetic isdone in CA PPM.