diff --git a/backup-mtime b/backup-mtime
new file mode 100755
index 0000000..1ae30f0
--- /dev/null
+++ b/backup-mtime
@@ -0,0 +1,7 @@
+#!/bin/sh
+# print out a shell script to restore mtime to the current state
+#
+# (may need gnu coreutils.)
+#
+find "$@" -exec \
+  stat --format="touch --no-dereference -m -d '%y' '%n'" {} \;