diff --git a/cpdf.ml b/cpdf.ml
index 4b62539..964dfa1 100644
--- a/cpdf.ml
+++ b/cpdf.ml
@@ -3399,6 +3399,9 @@ let set_pdf_info_xml_many only_when_present changes value xmldata pdf =
       changes;
     !xmldata
 
+(* Set metadata date *)
+let set_metadata_date pdf only_when_present date = pdf
+
 (* \section{Set an entry in the /Info dictionary} *)
 
 (* We must parse the date to get its components, then use strftime to build the
@@ -3429,10 +3432,11 @@ let default_date () =
 (* XMP date format is YYYY-MM-DDThh:mm:ssTZD *)
 let make_xmp_date_from_components d =
   let tzd =
+    if d.ut_relationship = 0 && d.offset_hours = 0 && d.offset_minutes = 0 then "Z" else
     (if d.ut_relationship >=0 then "+" else "-") ^
-    Printf.sprintf "%2i" d.offset_hours ^
+    Printf.sprintf "%02i" d.offset_hours ^
     ":" ^
-    Printf.sprintf "%2i" d.offset_minutes
+    Printf.sprintf "%02i" d.offset_minutes
   in 
     Cpdfstrftime.strftime
       ~time:{Unix.tm_sec = d.second;
diff --git a/cpdf.mli b/cpdf.mli
index df53565..0b88bd9 100644
--- a/cpdf.mli
+++ b/cpdf.mli
@@ -195,6 +195,8 @@ val get_metadata : Pdf.t -> Pdfio.bytes option
 (** Print metadate to stdout *)
 val print_metadata : Pdf.t -> unit
 
+val set_metadata_date : Pdf.t -> string -> bool -> Pdf.t
+
 (** {2 Stamping} *)
 
 (** [combine_pages fast under over scaletofit swap equalize] combines the page
diff --git a/cpdfcommand.ml b/cpdfcommand.ml
index 0585447..e43885c 100644
--- a/cpdfcommand.ml
+++ b/cpdfcommand.ml
@@ -1589,6 +1589,9 @@ let setalsosetxmlwhenpresent () =
 let setjustsetxml () =
   args.justsetxml <- true
 
+let setsetmetadatadate d =
+  args.op <- Some (SetMetadataDate d)
+
 (* Parse a control file, make an argv, and then make Arg parse it. *)
 let rec make_control_argv_and_parse filename =
   control_args := !control_args @ parse_control_file filename
@@ -2039,6 +2042,9 @@ and specs =
    ("-remove-metadata",
        Arg.Unit (setop RemoveMetadata),
        " Remove document metadata");
+   ("-set-metadata-date",
+       Arg.String setsetmetadatadate,
+       " Set the XMP metadata date property");
    ("-hide-toolbar",
       Arg.String hidetoolbar,
       " Hide the viewer's toolbar");
@@ -3698,7 +3704,7 @@ let go () =
                  ~xmp_just_set:args.justsetxml
                  (key, value, version) pdf)
   | Some (SetMetadataDate date) ->
-      failwith "SetMetadataDate unimplemented"
+      write_pdf false (Cpdf.set_metadata_date (get_single_pdf args.op false) date args.alsosetxmlwhenpresent)
   | Some ((HideToolbar _ | HideMenubar _ | HideWindowUI _
           | FitWindow _ | CenterWindow _ | DisplayDocTitle _) as op) ->
       begin match args.out with