http://bugs.icu-project.org/trac/ticket/9367
--- common/putil.cpp.orig	2016-10-19 12:20:56.000000000 -0500
+++ common/putil.cpp	2017-02-11 10:01:49.000000000 -0600
@@ -119,6 +119,13 @@
 #endif
 
 /*
+ * Mac OS X 10.4 doesn't use its localtime_r() declaration in <time.h> if either _ANSI_SOURCE or _POSIX_C_SOURCE is #defined.
+ */
+#if defined(U_TZNAME) && U_PLATFORM_IS_DARWIN_BASED && (defined(_ANSI_SOURCE) || defined(_POSIX_C_SOURCE))
+U_CFUNC struct tm *localtime_r(const time_t *, struct tm *);
+#endif
+
+/*
  * Only include langinfo.h if we have a way to get the codeset. If we later
  * depend on more feature, we can test on U_HAVE_NL_LANGINFO.
  *
