diff --git a/src/tz.cpp b/src/tz.cpp
index 8231797..5191521 100644
--- a/src/tz.cpp
+++ b/src/tz.cpp
@@ -2704,7 +2704,8 @@ operator<<(std::ostream& os, const time_zone& z)
         os.width(8);
         os << s.format_ << "   ";
         os << s.until_year_ << ' ' << s.until_date_;
-        os << "   " << s.until_utc_ << " UTC";
+        os << "   ";
+        date::operator<<(os, s.until_utc_) << " UTC";
         os << "   " << s.until_std_ << " STD";
         os << "   " << s.until_loc_;
         os << "   " << make_time(s.initial_save_);