diff --git a/src/time/ISO8601.cxx b/src/time/ISO8601.cxx
index 32527d053..725215ea6 100644
--- a/src/time/ISO8601.cxx
+++ b/src/time/ISO8601.cxx
@@ -58,6 +58,8 @@ FormatISO8601(std::chrono::system_clock::time_point tp)
 	return FormatISO8601(GmTime(tp));
 }
 
+#ifndef _WIN32
+
 static std::pair<unsigned, unsigned>
 ParseTimeZoneOffsetRaw(const char *&s)
 {
@@ -167,6 +169,8 @@ ParseTimeOfDay(const char *s, struct tm &tm,
 	return end;
 }
 
+#endif
+
 std::pair<std::chrono::system_clock::time_point,
 	  std::chrono::system_clock::duration>
 ParseISO8601(const char *s)