+diff -up ./ext/date/config0.m4.systzdata ./ext/date/config0.m4
+--- ./ext/date/config0.m4.systzdata 2021-08-10 11:35:28.000000000 +0200
++++ ./ext/date/config0.m4 2021-08-10 12:09:41.067003517 +0200
+@@ -4,6 +4,19 @@ AC_CHECK_HEADERS([io.h])
+ dnl Check for strtoll, atoll
+ AC_CHECK_FUNCS(strtoll atoll)
+
++PHP_ARG_WITH(system-tzdata, for use of system timezone data,
++[ --with-system-tzdata[=DIR] to specify use of system timezone data],
++no, no)
++
++if test "$PHP_SYSTEM_TZDATA" != "no"; then
++ AC_DEFINE(HAVE_SYSTEM_TZDATA, 1, [Define if system timezone data is used])
++
++ if test "$PHP_SYSTEM_TZDATA" != "yes"; then
++ AC_DEFINE_UNQUOTED(HAVE_SYSTEM_TZDATA_PREFIX, "$PHP_SYSTEM_TZDATA",
++ [Define for location of system timezone data])
++ fi
++fi
++
+ PHP_DATE_CFLAGS="-I@ext_builddir@/lib -DZEND_ENABLE_STATIC_TSRMLS_CACHE=1 -DHAVE_TIMELIB_CONFIG_H=1"
+ timelib_sources="lib/astro.c lib/dow.c lib/parse_date.c lib/parse_tz.c
+ lib/timelib.c lib/tm2unixtime.c lib/unixtime2tm.c lib/parse_iso_intervals.c lib/interval.c"