using Microsoft.Office.Interop.Word; Application app = new Application(); Document doc = app.Documents.Add(); doc.AddCreationDate(DateTime.Now);
using iTextSharp.text; using iTextSharp.text.pdf; PdfReader reader = new PdfReader("input.pdf"); PdfStamper stamper = new PdfStamper(reader, new FileStream("output.pdf", FileMode.Create)); stamper.MoreInfo.AddCreationDate(DateTime.Now); stamper.Close();Package library: iTextSharp.