hwclock

hwclock – query and set the hardware clock (RTC)

hwclock is a tool for accessing the Hardware Clock. You can display the current time, set the Hardware Clock to a specified time, set the Hardware Clock to the System Time, and set the System Time from the Hardware Clock.

You can also run hwclock periodically to insert or remove time from the Hardware Clock to compensate for systematic drift (where the clock consistently gains or loses time at a certain rate if left to run).

 

hwclock -r or hwclock –show
hwclock -w or hwclock –systohc
hwclock -s or hwclock –hctosys
hwclock -a or hwclock –adjust
hwclock -v or hwclock –version
hwclock –set –date=newdate
hwclock –getepoch
hwclock –setepoch –epoch=yea