Fix tinderbox bustage generating build date; no bug.

calendar/lightning/Makefile.in

@@ -71,6 +71,11 @@ DEFINES += -DTHEME=$(THEME)
 DEFINES += -DTHUNDERBIRD_VERSION=$(THUNDERBIRD_VERSION)
 DEFINES += -DFIREFOX_VERSION=$(FIREFOX_VERSION)
 
+DEFINES += -DTARGET_PLATFORM=$(OS_TARGET)_$(TARGET_XPCOM_ABI)
+
+MOZ_BUILD_DATE = $(shell $(PERL) -I$(TOPSRCDIR)/config $(TOPSRCDIR)/config/bdate.pl)
+DEFINES += -DMOZ_BUILD_DATE=$(MOZ_BUILD_DATE)
+
 PREF_JS_EXPORTS = $(srcdir)/content/lightning.js
 
 include $(topsrcdir)/config/rules.mk