CentOS - Mar 2007 - using true UTC timezone everywhere

One problem with the daylight savings is that they mess with reporting 
tools that use timestamps. I guess an application could be configured to 
log UTC instead of local time, but that's not always doable.
Also, if you have servers in several different timezones, it's better if 
all systems follow the same clock.

So, I'm thinking it's perhaps better if I just use ZONE="UTC"
on all
systems. These are the steps I can think of so far:

- make sure the BIOS clock is set to UTC
- run timeconfig and make sure "System Clock uses UTC" is checked
- cp /usr/share/zoneinfo/UTC /etc/localtime
- edit /etc/sysconfig/clock and set ZONE="UTC"
- reboot

Voila - instant UTC clock. Never need to worry about daylight savings again.

Anybody can think of any problems with:
- the procedure I described?
- the simple fact of using the "true" UTC timezone?

-- 
Florin Andrei

http://florin.myip.org/

On Thu, Mar 08, 2007 at 12:04:03PM -0800, Florin Andrei
wrote:
> - make sure the BIOS clock is set to UTC
> - run timeconfig and make sure "System Clock uses UTC" is checked
The above aren't even necessary if your local time is also UTC.
> Anybody can think of any problems with:
> - the procedure I described?
> - the simple fact of using the "true" UTC timezone?
You might accidentally be eight hours early for appointments?

-- 
Matthew Miller           mattdm at mattdm.org         
<http://mattdm.org/>
Boston University Linux      ------>             
<http://linux.bu.edu/>

Florin Andrei spake the following on 3/8/2007 12:04 PM:
> One problem with the daylight savings is that they mess with reporting
> tools that use timestamps. I guess an application could be configured to
> log UTC instead of local time, but that's not always doable.
> Also, if you have servers in several different timezones, it's better
if
> all systems follow the same clock.
> 
> So, I'm thinking it's perhaps better if I just use
ZONE="UTC" on all
> systems. These are the steps I can think of so far:
> 
> - make sure the BIOS clock is set to UTC
> - run timeconfig and make sure "System Clock uses UTC" is checked
> - cp /usr/share/zoneinfo/UTC /etc/localtime
> - edit /etc/sysconfig/clock and set ZONE="UTC"
> - reboot
> 
> Voila - instant UTC clock. Never need to worry about daylight savings
> again.
> 
> Anybody can think of any problems with:
> - the procedure I described?
> - the simple fact of using the "true" UTC timezone?
> 
System spikes caused by logrotation happening in the middle of the workday?
Not a real problem, but the first one I could think of.

-- 

MailScanner is like deodorant...
You hope everybody uses it, and
you notice quickly if they don't!!!!

Florin Andrei wrote:
> layer to the PHP page that will display those logs and optionally 
> convert the timestamps to local time on-the-fly, if that's what the
user
> wants.
But then you've just moved the DST issue into your application and not
really solved much at all :-)

-- 

rgds
Stephen