diff --git a/src/lldp_syncd/daemon.py b/src/lldp_syncd/daemon.py
index c248a06..8177826 100644
--- a/src/lldp_syncd/daemon.py
+++ b/src/lldp_syncd/daemon.py
@@ -43,9 +43,17 @@ def parse_time(time_str):
             return sage;
     }
     :return: parsed age in time ticks (or seconds)
+             0 on invalid time_str
     """
+    if '-' in time_str:
+        return 0 
+
     days, hour_min_secs = re.split(LLDPD_UPTIME_RE_SPLIT_PATTERN, time_str)
-    struct_time = time.strptime(hour_min_secs, LLDPD_TIME_FORMAT)
+    try:
+        struct_time = time.strptime(hour_min_secs, LLDPD_TIME_FORMAT)
+    except ValueError:
+        logger.warning("Invalid time {}, possibly system time changed?".format(hour_min_secs))
+        return 0
     time_delta = datetime.timedelta(days=int(days), hours=struct_time.tm_hour,
                                     minutes=struct_time.tm_min,
                                     seconds=struct_time.tm_sec)
diff --git a/tests/test_lldpSyncDaemon.py b/tests/test_lldpSyncDaemon.py
index 1302fc1..7d84d0d 100644
--- a/tests/test_lldpSyncDaemon.py
+++ b/tests/test_lldpSyncDaemon.py
@@ -96,6 +96,10 @@ def test_sync_roundtrip(self):
     def test_timeparse(self):
         self.assertEquals(lldp_syncd.daemon.parse_time("0 day, 05:09:02"), make_seconds(0, 5, 9, 2))
         self.assertEquals(lldp_syncd.daemon.parse_time("2 days, 05:59:02"), make_seconds(2, 5, 59, 2))
+        self.assertEquals(lldp_syncd.daemon.parse_time("2 days, -05:-59:-02"), make_seconds(0, 0, 0, 0))
+        self.assertEquals(lldp_syncd.daemon.parse_time("-2 days, 05:59:02"), make_seconds(0, 0, 0, 0))
+        self.assertEquals(lldp_syncd.daemon.parse_time("0 days, 00:00:-02"), make_seconds(0, 0, 0, 0))
+        self.assertEquals(lldp_syncd.daemon.parse_time("0 days, 00:-10:00"), make_seconds(0, 0, 0, 0))
 
     def parse_mgmt_ip(self, json_file):
         parsed_update = self.daemon.parse_update(json_file)