Currently, only some PDF metadata are copied to DT metadata on import (author, title, subject, URL and keywords). Other, lie creation and modification date, are ignored – although they’re available in the PDF, DT does not show them anywhere (see this sample PDF https://doi.org/10.6028/NIST.CSWP.04162018).
Creation and modification date are standard PDF metadata (cf PDF - Wikipedia). I’d suggest adding them to the set of metadata visible in DT.
If there’s a naming clash between DT’s and the PDF’s creation date, the PDF one could be called
PDFcreation date or so. The first request of this kind actually dates back to 2015