--- Desktop/lpdf-sig.lmt	2024-12-10 19:47:10.259900550 +0100
+++ lpdf-sig.lmt	2024-12-10 20:00:27.168094593 +0100
@@ -84,6 +84,7 @@
                 Filter       = pdfconstant("Adobe.PPKLite"),
                 SubFilter    = pdfconstant("adbe.pkcs7.detached"),
                 Type         = pdfconstant("Sig"),
+                M            = lpdf.pdftimestamp(os.date("%Y-%m-%dT%H:%M:%S") .. os.timezone()),
              -- Reasons      = pdfunicode("just to be sure"),
                 Reference    = reference,
             }