timed: gate time setting on GPS fix (#34217)

system/timed.py

@@ -5,7 +5,7 @@ import time
 from typing import NoReturn
 
 import cereal.messaging as messaging
-from openpilot.common.time import system_time_valid
+from openpilot.common.time import min_date, system_time_valid
 from openpilot.common.swaglog import cloudlog
 from openpilot.common.params import Params
 from openpilot.common.gps import get_gps_location_service
@@ -26,10 +26,10 @@ def set_time(new_time):
 
 def main() -> NoReturn:
   """
-    timed has one responsibility:
+    timed has two responsibilities:
-    - getting the current time
+    - getting the current time from GPS
+    - publishing the time in the logs
 
-    GPS directly gives time.
     AGNOS will also use NTP to update the time.
   """
 
@@ -47,14 +47,15 @@ def main() -> NoReturn:
     pm.send('clocks', msg)
 
     gps = sm[gps_location_service]
+    gps_time = datetime.datetime.fromtimestamp(gps.unixTimestampMillis / 1000.)
     if not sm.updated[gps_location_service] or (time.monotonic() - sm.logMonoTime[gps_location_service] / 1e9) > 2.0:
       continue
+    if not gps.hasFix:
+      continue
+    if gps_time < min_date():
+      continue
 
-    # set time
-    # TODO: account for unixTimesatmpMillis being a (usually short) time in the past
-    gps_time = datetime.datetime.fromtimestamp(gps.unixTimestampMillis / 1000.)
     set_time(gps_time)
-
     time.sleep(10)
 
 if __name__ == "__main__":