diff --git a/src/util/tag b/src/util/tag
index db084da0a..3518b82e0 100755
--- a/src/util/tag
+++ b/src/util/tag
@@ -1,9 +1,14 @@
 #!/bin/sh
-k="CVS `date +"%Y-%m-%d %H:%M"`"
+k=".`date +"%d%H%M"`"
 file="src/lsp/config.lsp.in"
-if [ -f $file  ]; then
-  echo "Tagging ECL with date $k"
-  sed "s,@PACKAGE_VERSION@.*\",@PACKAGE_VERSION@ ($k)\",g" < $file > foo && \
+if test -f $file ; then
+  if test -z "$1" ; then
+    echo "Tagging ECL with $k"
+  else
+    echo "Untagging ECL"
+    k=""
+  fi
+  sed "s,@PACKAGE_VERSION@.*\",@PACKAGE_VERSION@$k\",g" < $file > foo && \
     mv foo $file && grep PACKAGE_VERSION $file
 else
   echo "Cannot find file to tag"