move version string overrides to separate file

configure/CONFIG_SITE

@@ -157,9 +157,7 @@ USE_POSIX_THREAD_PRIORITY_SCHEDULING = YES
 
 # Site version number, if set will append '-' and this string to the
 #  EPICS version number string that is reported by many tools.
-ifeq ($(INSTALL_LOCATION),$(EPICS_BASE))
-EPICS_SITE_VERSION=$(shell $(PERL) -MPOSIX -e 'print strftime "%Y-%m-%d", localtime')
-endif
+EPICS_SITE_VERSION =
 
 # For GNU compiler, use pipes rather than temporary files for
 #  communication between the various stages of compilation.

configure/CONFIG_SITE.local

@@ -0,0 +1,4 @@
+# Add build date to version string
+ifeq ($(INSTALL_LOCATION),$(EPICS_BASE))
+EPICS_SITE_VERSION=$(shell $(PERL) -MPOSIX -e 'print strftime "%Y-%m-%d", localtime')
+endif