diff --git a/SystemTools.cxx b/SystemTools.cxx
index 6b4ad1a1336c0df6d1b4dd34bb4c84889ce8de2e..c09001be2c3c8fa1bb12410c01feded2d3dc9408 100644
--- a/SystemTools.cxx
+++ b/SystemTools.cxx
@@ -3980,6 +3980,10 @@ kwsys_stl::string SystemTools::GetParentDirectory(const char* fileOrDir)
 
 bool SystemTools::IsSubDirectory(const char* cSubdir, const char* cDir)
 {
+  if(!*cDir)
+    {
+    return false;
+    }
   kwsys_stl::string subdir = cSubdir;
   kwsys_stl::string dir = cDir;
   SystemTools::ConvertToUnixSlashes(dir);
diff --git a/kwsysDateStamp.cmake b/kwsysDateStamp.cmake
index 21aeaab9f2ed06069609115e5fca6e1616bd3fdf..65f81e6ca20c3bc139e4e49e6c36817fbef2a637 100644
--- a/kwsysDateStamp.cmake
+++ b/kwsysDateStamp.cmake
@@ -7,4 +7,4 @@ SET(KWSYS_DATE_STAMP_YEAR  2009)
 SET(KWSYS_DATE_STAMP_MONTH 04)
 
 # KWSys version date day component.  Format is DD.
-SET(KWSYS_DATE_STAMP_DAY   15)
+SET(KWSYS_DATE_STAMP_DAY   20)