ntp/systemd/ntp-wait.service

   1 [Unit]
   2 Description=Wait for ntpd to synchronize system clock
   3 After=ntpd.service
   4 Requires=ntpd.service
   5 Before=time-sync.target
   6 Wants=time-sync.target
   7
   8 [Service]
   9 Type=oneshot
  10 ExecStart=/usr/sbin/ntp-wait
  11 RemainAfterExit=yes
  12
  13 [Install]
  14 WantedBy=multi-user.target