debian/apt-daily.timer

   1 [Unit]
   2 Description=Daily apt activities
   3
   4 [Timer]
   5 OnCalendar=*-*-* 6,18:00
   6 RandomizedDelaySec=12h
   7 AccuracySec=1h
   8 Persistent=true
   9
  10 [Install]
  11 WantedBy=timers.target