Source: https://gitlab.com/gpsd/gpsd/-/issues/340
Thanks-to: James Browning

--- a/libgps/gpsutils.c
+++ b/libgps/gpsutils.c
@@ -833,7 +833,7 @@ timespec_t iso8601_to_timespec(const char *isotime)
     if (1 < sl.size()) {
         usec = sl[1].toInt() / pow(10., (double)sl[1].size());
     }
-    ret.tv_sec = d.toTime_t();
+    ret.tv_sec = d.toSecsSinceEpoch();
     ret.tv_nsec = usec * 1e9;
 #else  // USE_QT
     double usec = 0;