--- freerdp-3.11.0/winpr/libwinpr/timezone/timezone.c.old
+++ freerdp-3.11.0/winpr/libwinpr/timezone/timezone.c
@@ -382,7 +382,24 @@
 static LONG get_gmtoff_min(const struct tm* t)
 {
 	WINPR_ASSERT(t);
+#if defined(__sun)
+/* port code from https://docs.diesel.rs/1.4.x/src/chrono/sys/unix.rs.html */
+	long gmtoff;
+
+	tzset();
+	if (t->tm_isdst == 0) {
+		gmtoff = -(timezone/60);
+	}
+	else if (t->tm_isdst > 0) {
+		gmtoff = -(altzone/60);
+	}
+	else { /* assume not in dst */
+		gmtoff = -(timezone/60);
+	}
+	return gmtoff;
+#else
 	return -(LONG)(t->tm_gmtoff / 60l);
+#endif
 }
 
 static struct tm next_day(const struct tm* start)
@@ -779,11 +796,20 @@
 	tzid = winpr_guess_time_zone();
 	if (!map_iana_id(tzid, pTimeZoneInformation))
 	{
+#if defined(__sun)
+		const bool is_dst = local_time->tm_isdst > 0;
+		const size_t len = TimeZoneIanaAbbrevGet(tzname[is_dst], NULL, 0);
+#else
 		const size_t len = TimeZoneIanaAbbrevGet(local_time->tm_zone, NULL, 0);
+#endif
 		list = (const char**)calloc(len, sizeof(const char*));
 		if (!list)
 			goto out_error;
+#if defined(__sun)
+		const size_t size = TimeZoneIanaAbbrevGet(tzname[is_dst], list, len);
+#else
 		const size_t size = TimeZoneIanaAbbrevGet(local_time->tm_zone, list, len);
+#endif
 		for (size_t x = 0; x < size; x++)
 		{
 			const char* id = list[x];