Updating and displaying CMOS clock

Jesse Gooch lists at gooch.io
Sun Jul 6 21:15:03 UTC 2014

Hi Victor,

On 06/07/14 08:32 AM, Victor Sudakov wrote:
> Colleagues,
> What's the command to update the CMOS clock to the time of the kernel
> clock? 
> ntpd does a good job of keeping the accurate time in the kernel clock,
> but from my experience, this time is not propagated to the CMOS clock
> which lives its own life. As a result, there is a large time skew
> everytime the box is rebooted, which prevents from Kerberos login
> until the kernel clock is synchronized.
> In other words, what's the FreeBSD equivalent of the Linux 
> "hwclock --systohc" command? 
> And no, contrary to popular belief, the correction of the CMOS clock
> does not happen automatically in FreeBSD even if ntpd is running.
> If there is a way to display the time of the CMOS (RTC) clock, I
> would be interested to know too.
> TIA.

To get around this I've started using ntpdate on boot. You can put the
following in your /etc/rc.conf:

ntpdate_flags="<time server here>"

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