So, if you do not double boot with Windows - reset your BIOS to UTC and problems solved.
Duh. I thought everyone knew that!
That’s a good idea, to reset the BIOS to UTC (for those of us who don’t use Windows).
When I was installing 12.2, I saw the following message when I unchecked the box next to “Hardware Clock Set To UTC”:
You selected local time, but only Linux seems to be installed on your system. In such case, it is strongly recommended to use UTC, and to click Cancel.
If you want to keep local time, you must adjust the CMOS clock twice the year because of Day Light Saving switches. If you miss to adjust the clock, backups may fail, your mail system may drop mail messages,etc.
If you use UTC, the Linux will adjust the time automatically.
Do you want to continue with your selection (local time)?
Well, I first started using openSUSE only back in April, so I haven’t seen what happens in this distro when Daylight Saving time switches. I have several other distros installed in multi-boot set-ups on two computers, but I haven’t noticed any problems when the time changes. I haven’t really had any big problems with not using UTC in my all-Linux set-ups until I installed 12.2 (and that’s taken care of now, too).
Still, it makes sense to just go ahead and change it in the BIOS, even though I think that then I’ll have to go and fix the time in each of my Linux installations.
Normally when a Linux/Unix system shuts down (goes to run level 0) it executes:
hwclock --systohc
This makes complications when different systems on the same hardware are setting the hardware clock to different times.
At boot time the system time is read from the hardware clock, and if your OS thinks that the hwclock is set to local time, modified with respect to the local timezone, so that system time is at UTC. If/when NTP is operational this will then start adjusting system time to match UTC with the time servers.
Apart from Microsoft, who like to be awkward, system time (and the hardware clock) is always UTC. The time displayed to the local users is offset from UTC depending on the timezone file and their locale settings. The timezone file is updated regularly to reflect changes in “Daylight Saving times” and time zones by various governments.
On 2012-09-10 06:16, MALsPa wrote:
>> -IF YOU WANT TO KEEP LOCAL TIME, YOU MUST ADJUST THE CMOS CLOCK TWICE
>> THE YEAR BECAUSE OF DAY LIGHT SAVING SWITCHES. IF YOU MISS TO ADJUST THE
>> CLOCK, BACKUPS MAY FAIL, YOUR MAIL SYSTEM MAY DROP MAIL MESSAGES,ETC.-
>>
>> -IF YOU USE UTC, THE LINUX WILL ADJUST THE TIME AUTOMATICALLY.-
>>
>> -DO YOU WANT TO CONTINUE WITH YOUR SELECTION (LOCAL TIME)?-
>
> Well, I first started using openSUSE only back in April, so I haven’t
> seen what happens in this distro when Daylight Saving time switches.
No, because this is new in 12.2. Previous versions attempted to do the daylight adjustment to the
cmos clock kept as local time, but the problem is that Windows also tried to do the same! So the
openSUSE devs gave up and quit trying.
If all operating systems using the same macchine assume the clock is UTC (even Windows) then all the
problems disappear.
Actually, you do not do any change in the bios. What you change is the assumption by the system that
the bios keeps local or utc time. If the bios would keep not only the time but the name of the
locale it uses, then the problem would also disappear.
I mean: If I say it is 12:00, do you know what time it really is? But if I say:
Mon Sep 10 12:43:08 CEST 2012
the thing is clearer. And if it also adds the shift, better:
Mon, 10 Sep 2012 12:43:44 +0200 (CEST)
–
Cheers / Saludos,
Carlos E. R.
(from 11.4 x86_64 “Celadon” (Minas Tirith))
Huh? Change it in the BIOS, or not?
On 2012-09-10 12:46, eng-int wrote:
> Apart from Microsoft, who like to be awkward, system time (and the
> hardware clock) is always UTC.
No, they are not awkward, they are simply inheriting a compatible system; they try to keep things
compatible at the cost of holding off some features and progress. It is their policy.
The first PCs did not have a cmos, we had to type the time and date on every boot. Soon someone
designed an add-on card with a clock, which could be read by an add-on software and set the system
(cpu) clock without bothering the user to type it. It was not Microsoft who did this.
Soon PCs started to be made with that CMOS clock included in the motherboard - I don’t remember if
it was the IBM-XT or AT models who did this. It was a CMOS chip with a clock and some memory, both
kept from a battery. That memory was used to store the BIOS configuration data - even today.
Note that the problem is not that the cmos clock uses utc or not, it is that
the time locale it uses is unknown: the cmos clock, a piece of ancient hardware
doesn’t keep track of this, or if it does, the different oses don’t use it.
So the operating system bios took to read that chip clock at system start and set the clock, using
local time because that’s the only thing MSDos did know about (same as the FAT filesystem). Windows
later was simply made compatible with that procedure later.
Currently Windows 7 can use UTC instead.
–
Cheers / Saludos,
Carlos E. R.
(from 11.4 x86_64 “Celadon” (Minas Tirith))
On 2012-09-10 19:06, MALsPa wrote:
>
> farcusnz;2485506 Wrote:
>> So, if you do not double boot with Windows - reset your BIOS to UTC and
>> problems solved.
>
> robin_listas;2485630 Wrote:
>> Actually, you do not do any change in the bios. What you change is the assumption by the system that
>> the bios keeps local or utc time. If the bios would keep not only the time but the name of the
>> locale it uses, then the problem would also disappear.
>
> Huh? Change it in the BIOS, or not?
How? Show me a photo of the bios configuration page where you can change the clock to be UTC or
local or whatever. I would like to see that.
–
Cheers / Saludos,
Carlos E. R.
(from 11.4 x86_64 “Celadon” (Minas Tirith))
Hi
Only the time and date, you need to make an informed decision as to
what the current UTC time is… I just set it from linux to utc and be
done, then use ntp. I guess I could use a cron job to adjust it via
ntp…
–
Cheers Malcolm °¿° (Linux Counter #276890)
openSUSE 12.2 (x86_64) Kernel 3.4.6-2.10-desktop
up 0:28, 3 users, load average: 0.12, 0.13, 0.12
CPU Intel i5 CPU M520@2.40GHz | Intel Arrandale GPU
On 2012-09-10 22:22, malcolmlewis wrote:
> Hi
> Only the time and date, you need to make an informed decision as to
> what the current UTC time is… I just set it from linux to utc and be
> done, then use ntp. I guess I could use a cron job to adjust it via
> ntp…
So, you do not change the bios, you change the system. As I said. 
–
Cheers / Saludos,
Carlos E. R.
(from 11.4 x86_64 “Celadon” (Minas Tirith))
one things that confuses me slightly about the clock in Opensuse is that there is an option to configure the clock via ntp in KIDE and a separate option to configure the clock via ntp in yast.
Why the double up - and should one be used over the other?
Any harm in setting both to use ntp (although I imagine a bit pointless).
Are you sure they are not one and the same
This is what confuses me - because they both require root privileges.
However, they don’t contain the same set of ntp servers.
Setting the ntp server in the kde clock - go to yast and the ntp servers are still unset. So they seem to operate independently.
I’m in front of my 12.2 gnome (netbook) ATM, but I only use Yast to set up mine
And you guys are like a dog with a bone… I never though there could be so much fuss over this.
Hi,
Just loaded openSUSE-12.2- 586-dvd.iso (KDE Desktop) on my Dell-Inspiron Laptop.
I find another problem with the ‘Digital Clock’ Widget: When i try to adjust the time and date and click on ‘Apply’, i get the following error:
“Error Kde Control Module: Unable to authenticate/execute the action:3,”
I fail to get any idea for solving this problem. Help would be highly appreciated.
Randhir Phagura
@rsp2
Dunno, I always adjust the time in Yast and pretty much regardless whether I have windows or not on a machine I still use NTP
Hi
I do note in YaST /etc/sysconfig editor under Environment -> Clock
there are some systohc and hwclock settings, on my system USE_HWCLOCK is
set to yes.
–
Cheers Malcolm °¿° (Linux Counter #276890)
openSUSE 12.2 (x86_64) Kernel 3.4.6-2.10-desktop
up 18:18, 3 users, load average: 0.04, 0.11, 0.11
CPU Intel i5 CPU M520@2.40GHz | Intel Arrandale GPU
Okay, good, I was only trying to get some clarification on that point. Went into my own BIOS and saw that you can only change the date and time.
In my case – 8 different Linux installations on this particular machine, for example, with each of them currently not using UTC – perhaps changing everything back to UTC would be more hassle than it’s worth.
Good info in this thread.
Couple of thoughts on the clock issue, seems like there was some change since last year release.
There should really be a way to set hardware clock to read only from within BIOS.
My problem is that I use local time on multiple systems and I set time manually in BIOS.
I’ve tried UTC and it changes hardware clock so other systems run into problems (+2h or -2h)
I’ve tried ntp, then system hangs on boot ntp sync if it happens to be disconnected.
I think USE_HWCLOCK=“no” temporarily fixed this offset for me, still looking into it…
On 2012-09-11 18:46, MALsPa wrote:
> Okay, good, I was only trying to get some clarification on that point.
> Went into my own BIOS and saw that you can only change the date and
> time.
Exactly - and there is no way to know what locale it is on.
> In my case – 8 different Linux installations on this particular
> machine, for example, with each of them currently -not- using UTC –
> perhaps changing everything back to UTC would be more hassle than it’s
> worth.
If all the systems are Linux, you should tell all of them that the bios is using utc time, it
is the least problematic setting.
If you also use Windows 7, you can do the same thing in W7, there is a documented registry
change for this to work.
If you use XP, then you do have to use local time in the bios.
Other oses, I do not know.
And yes, 12.2 is quite different in this respect than all previous openSUSE and SUSE versions,
they did a big change.
–
Cheers / Saludos,
Carlos E. R.
(from 12.1 x86_64 “Asparagus” at Telcontar)
Thanks a lot. The time was adjusted via Yast.
Randhir Phagura