PeachPDF
PeachPDF.PdfDocumentMetadata
PdfDocumentMetadata.CreationDate Property
Overrides the PDF document’s creation date. When non-null, wins over any date extracted
from the HTML source; when null (the default), the HTML-extracted date is used unchanged.
Required (directly or via a <meta> date in the source HTML) whenever an XMP
metadata stream is written (EnableXmpMetadata or
PdfAConformance) - xmp:CreateDate needs a real value,
and generation throws rather than writing a default/placeholder date if neither is present.
public System.Nullable<System.DateTimeOffset> CreationDate { get; set; }