From what I've found, GP doesn't tag the time to the majority of the date fields so you'll always see the 00:00:00:000 time indicator for those date fields. Some tables you will see a DEX_ROW_TS where that will show the time as well as the date. Unfortunately it doesn't look like the POP or the IV tables for the receipts have the DEX_ROW_TS field in them.
If you really need the timestamp you may need to look in to an auditing tool like Fastpath or Rockton.