This service updates the system clock via NTP every 4 hours.
If you're not in France, change 0.fr.pool.ntp.org to a NTP
server pool more fitting your location.
See www.ntp.pool.org for details.

Do yourself a favor and don't rely on NTP internally.
Just synchronize your main time server via this NTP client
to the outside world, and use a saner and simpler protocol
like TAICLOCK in your internal, fast-speed network.