# It can take several minutes before ntpd selects a server to synchronize with;
# try checking after 17 minutes (1024 seconds).

    alarm: system_clock_sync_state
       on: system.clock_sync_state
       os: linux
    class: Errors
     type: System
component: Clock
     calc: $state
    units: synchronization state
    every: 10s
     warn: $system.uptime.uptime > 17 * 60 AND $this == 0
    delay: down 5m
     info: when set to 0, the system kernel believes the system clock is not properly synchronized to a reliable server
       to: silent