Target Timer + Entry Variable

I have been able to set a Target Timer to release enactments on a specific number of days before a (datetime) Entry Variable, but I have not been able to get the time on that day to work.  For example, I use an Entry Variable "PERIOD_ENDS" which is a datetime field included in the SQL View that pulls enactments into the Program.  Say PERIOD_ENDS = 2018-03-31 00:00:00.0 and I set the Target Timer to 04:00 pm on 8 Days Before PERIOD_ENDS.  I would expect that Target Timer to release the enactment at 04:00 pm on 2018-03-23, but instead it releases