diff --git a/Performance.md b/Performance.md
index 10c9188..8ff750c 100644
--- a/Performance.md
+++ b/Performance.md
@@ -18,7 +18,7 @@ Some other notes on memory footprint:
  * importing nevow and twisted.web (for the web interface) raises the static
    footprint by about 3MB (from 12.8MB to 15.7MB).
 
- * importing pycryptopp (which began on 09-Nov-2007) raises the static footprint
+ * importing pycryptopp (which began on 2007-11-09) raises the static footprint
    (on a 32-bit machine) by about 6MB (from 19MB to 25MB). The 64-bit machine
    footprint was raised by 17MB (from 122MB to 139MB).