timesync – synchronize the system clock to a time source

aux/timesync [ –a accuracy ] [ –S stratum ] [ –s netroot ] [ –frnDdLilG ] [ timeserver ]

Aux/timesync synchronizes the system clock to a time source, by default a file server. The options are:
f    synchronize to a file server. If timeserver is missing, use /srv/boot.
r    synchronize to the local real time clock, #r/rtc.
L    used with –r to indicate the real time clock is in local time rather than GMT. This is useful on PCs that also run the Windows OS.
n    synchronize to an NTP server. If timeserver is missing, dial the server udp!$ntp!ntp.
D    print debugging to standard error
d    put file containing last determined clock frequency in directory dir, default /tmp.
i    stands for impotent. Timesync announces what it would do but doesn't do it. This is useful for tracking alternate time sources.
a    specifies the accuracy in nanoseconds to which the clock should be synchronized. This determines how often the reference clock is accessed.
G    causes timesync to use a gps server (see gpsfs(8)) as a time source.
s    causes timesync to listen for UDP NTP requests on the network rooted at netroot. Up to 4 –s options are allowed.
S    sets the stratum number to stratum.
l    turns on logging to /sys/log/timesync.

/tmp/ts.<sysname>.<type>.timeserver   where the last frequency guess is kept
/sys/log/timesync                   log file