diff --git a/development/scons/scons_manifest.py b/development/scons/scons_manifest.py
index 40975c4f1b..9bba189f3d 100644
--- a/development/scons/scons_manifest.py
+++ b/development/scons/scons_manifest.py
@@ -2142,6 +2142,7 @@ lib_scripts_files = Split('''
     TeXFiles.py
     clean_dvi.py
     convertDefault.py
+    date.py
     fen2ascii.py
     fig2pdftex.py
     fig2pstex.py
diff --git a/lib/Makefile.am b/lib/Makefile.am
index b6435d7a24..cc599f9061 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -920,6 +920,7 @@ dist_scripts_PYTHON = \
 	scripts/TeXFiles.py \
 	scripts/clean_dvi.py \
 	scripts/convertDefault.py \
+	scripts/date.py \
 	scripts/fen2ascii.py \
 	scripts/fig2pdftex.py \
 	scripts/fig2pstex.py \
diff --git a/lib/configure.py b/lib/configure.py
index f292567266..5ee827c275 100644
--- a/lib/configure.py
+++ b/lib/configure.py
@@ -438,7 +438,7 @@ def checkConverterEntries():
     #
     # Entried that do not need checkProg
     addToRC(r'''\converter lyxpreview ppm        "python -tt $$s/scripts/lyxpreview2bitmap.py"	""
-\converter date       dateout    "date +%d-%m-%Y > $$o"	""
+\converter date       dateout    "python -tt $$s/scripts/date.py %d-%m-%Y > $$o"	""
 \converter docbook    docbook-xml "cp $$i $$o"	"xml"
 \converter fen        asciichess "python -tt $$s/scripts/fen2ascii.py $$i $$o"	""
 \converter fig        pdftex     "python -tt $$s/scripts/fig2pdftex.py $$i $$o"	""
diff --git a/lib/scripts/date.py b/lib/scripts/date.py
new file mode 100755
index 0000000000..0228bc0a75
--- /dev/null
+++ b/lib/scripts/date.py
@@ -0,0 +1,33 @@
+#!/usr/bin/env python
+# -*- coding: iso-8859-1 -*-
+
+# file date.py
+# This file is part of LyX, the document processor.
+# Licence details can be found in the file COPYING.
+
+# \author Enrico Forestieri
+
+# Full author contact details are available in file CREDITS.
+
+# Print the system date and time in the given format. See the python
+# documentation for available formats (mostly the same as the POSIX std).
+# This file is provided because the date command on Windows is not
+# POSIX compliant.
+
+import sys
+from time import strftime
+
+def main(argv):
+    if len(argv) > 2:
+        sys.stderr.write('Usage: python date.py [<format>]\n')
+        sys.exit(1)
+
+    if len(argv) == 2:
+        format = argv[1]
+    else:
+        format = "%d-%m-%Y"
+
+    print strftime(format)
+
+if __name__ == "__main__":
+    main(sys.argv)
diff --git a/src/insets/ExternalSupport.C b/src/insets/ExternalSupport.C
index 93b7f9f212..8ed977b6d5 100644
--- a/src/insets/ExternalSupport.C
+++ b/src/insets/ExternalSupport.C
@@ -31,17 +31,19 @@
 #include "support/os.h"
 #include "support/package.h"
 #include "support/path.h"
-
 #include "support/std_ostream.h"
 
+#include <boost/filesystem/operations.hpp>
+
 namespace support = lyx::support;
 
 using std::endl;
-
 using std::ostream;
 using std::string;
 using std::vector;
 
+using boost::filesystem::is_directory;
+
 
 namespace lyx {
 namespace external {
@@ -254,7 +256,7 @@ void updateExternal(InsetExternalParams const & params,
 	string const temp_file =
 		support::MakeAbsPath(params.filename.mangledFilename(),
 				     m_buffer->temppath());
-	if (!abs_from_file.empty()) {
+	if (!abs_from_file.empty() && !is_directory(abs_from_file)) {
 		unsigned long const from_checksum = support::sum(abs_from_file);
 		unsigned long const temp_checksum = support::sum(temp_file);
 
diff --git a/status.14x b/status.14x
index 0f51944bef..2667aac848 100644
--- a/status.14x
+++ b/status.14x
@@ -237,6 +237,9 @@ What's new
 - add Aspell/Pspell's file extension for personal dictionary files
   in preferences (bug 895)
 
+- Fix hang/crash on Windows/Cygwin when using the external date inset
+  (bug 3220).
+
 * BUILD/INSTALLATION:
 
 - Allow autoconf 2.60 and 2.61 for building.