You may end up at some point where you need detailed statistics about time synchronization on your Linux machine. To achieve that, simply do the following :
1. Edit your NTP configuration file :
/etc/ntpd.conf
2. Append the following parameters :
statistics loopstats statsdir /var/log/ntpstats/ filegen peerstats file peers type day link enable filegen loopstats file loops type day link enable
3. Restart the NTP daemon :
service ntpd restart