diff --git a/wscript_build b/wscript_build
index 8390114ffc4..18f02dabd9d 100644
--- a/wscript_build
+++ b/wscript_build
@@ -14,6 +14,7 @@ try: set([1,2,3])
 except Exception: from Sets import set
 import re
 import zipfile,tarfile
+import time
 try:
   from os import chmod as _chmod,chown as _chown
   import pwd,stat,grp
@@ -41,10 +42,12 @@ def build_utils_docs ():
 # ant only needs to be reinvoked if the version with build number changes
 # we here trim all the depended targets from the target list:
 def build_jars ():
+	builddate = time.strftime("%Y.%m.%d.%H.%M.%S", time.localtime());
 	if Options.options.VERNUM:
 		Implementation_Version = Options.options.VERNUM
 	else:
 		Implementation_Version = "2.2"
+	Implementation_Version = Implementation_Version + "." + builddate
 
 	# this is to trigger recompilation / cache avoidance if the relevant environment for ant changes
 	ant_args = [