On Thu, 5 Mar 2015 21:05:09 -0500 Neal Murphy <neal.p.murphy@xxxxxxxxxxxx> wrote: > I was under the impression that a special tool is needed to set the > kernel TZ. What I did for Smoothwall 3.1 is set the hardware clock to > localtime and ensure that the system time is correctly pulled from > it. Then ensure that features that use '-m time' include the > --kerneltz option. I read that as well, but AFAIUI this program is deprecated and a "hwclock --systz" will do the job: man hwclock: --systz Set the kernel's timezone and reset the System Time based on the current timezone. > The bit I haven't done yet is implement a way to detect the local > time zone, determine the DST changeovers from the TZDATA package, > then schedule an at job for the two specific times when the kernel TZ > must be updated. Thus, if the system is running at that time, the > kernel TZ will be updated. If the system is not running at that time, > the kernel TZ will be correctly set the next time the system boots. > (This means that a system reboot will ensure the kernel TZ is > correct.) For the moment I simply put a "/sbin/hwclock --systz" in /etc/rc.local and rebooted the machine to see what happens and the rules using --kerneltz indeed worked as expected at locatime. I need to reboot during summertime to see what happens. > The program to set the kerneltz is 'setknltz' by David Madore. A cron > job runs at 0159 on 3/8 and 11/1 (for US/Eastern zone). The script > that is run sleeps for 1.02 seconds, then runs setknltz. Next, I > believe the rules that use '-m time' need to be reset so they have > the correct offset from UTC. We'll see what will happen on next March 29 at 3:00 AM. I have no idea if the xt_time module needs to be reloaded. I'll let you know within a few weeks. > I wrote some of this up on the smoothwall forum: > http://community.smoothwall.org/forum/viewtopic.php?p=332138#p332138 > and the fourth post below it. I might not be completely correct in my > assumptions, but I'm fairly sure the method will be sound. I have no idea how American DST changes are regulated, but in Europe DST changes take place om the last Sunday of March and October, which will be translated in a simple crontab entry: 0 3 25-31 3,10 0 /sbin/hwclock --systz (mind: wrong DST during 1 hour per year) R. -- ___________________________________________________________________ It is better to remain silent and be thought a fool, than to speak aloud and remove all doubt. +------------------------------------------------------------------+ | Richard Lucassen, Utrecht | +------------------------------------------------------------------+ -- To unsubscribe from this list: send the line "unsubscribe netfilter" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
