adjtimex – Display/Set the kernel time variables.
This program gives you raw access to the kernel time variables, like clock tick, frequency, offset, PPL Time constant, etc.
$ adjtimex -p — Print current kernel time values.
# adjtimex -w — Provide time details and ask the user to approximate the accuracy.
# adjtimex -c — Periodically (10Sec) compare the system clock with the CMOS clock values and give suggestions.
# adjtimex -t 100001 — Set the no of mSec that should be added to the system time for each kernel tick interrupt.
# adjtimex -f -408033 — Set the system clock frequency offset.
Read: man adjtimex