Represents the "ModDate" entry of the embedded file parameter dictionary object.

It is an optional entry defined as part of the PDF 1.0 specification.

It contains a string representing a PDF string object.

This is encoded as a date string. For details see the StringAtom.DateToString and StringAtom.StringToDate functions.

For definitive details see:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 46, page 104.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 45, page 137.