[svlug] revised timezone info posted Feb 26

[Rick Kwan]

I just updated my machine at work for the new Daylight Savings Time, which
starts March 11, and ran into a little surprise along the way.  Many web 
pages
say to grab the new timezone file via:
    wget ftp://elsie.nci.nih.gov/pub/tzdata2007b.tar.gz
That file no longer exists; it has been replaced by 'tzdata2007c.tar.gz'.
Internally, it looks like 'northamerica' was updated on Feb. 26, 2007.

There is an article at TechRepublic:
    http://articles.techrepublic.com.com/5100-10877_11-6163042.html
which shows the following example for Mountain Time after update.
--------
/etc/localtime  Sun Mar 11 08:59:59 2007 UTC = Sun Mar 11 02:59:59 2007 
MST isdst=0 gmtoff=-25200
/etc/localtime  Sun Mar 11 09:00:00 2007 UTC = Sun Mar 11 04:00:00 2007 
MDT isdst=1 gmtoff=-21600
/etc/localtime  Sun Nov  4 07:59:59 2007 UTC = Sun Nov  4 02:59:59 2007 
MDT isdst=1 gmtoff=-21600
/etc/localtime  Sun Nov  4 08:00:00 2007 UTC = Sun Nov  4 02:00:00 2007 
MST isdst=0 gmtoff=-25200
--------

But when I execute the following command for Mountain Time
    /usr/sbin/zdump -v /usr/share/zoneinfo/MST7MDT | grep 2007
I get something different:
--------
/usr/share/zoneinfo/MST7MDT  Sun Mar 11 08:59:59 2007 UTC = Sun Mar 11 
01:59:59 2007 MST isdst=0 gmtoff=-25200
/usr/share/zoneinfo/MST7MDT  Sun Mar 11 09:00:00 2007 UTC = Sun Mar 11 
03:00:00 2007 MDT isdst=1 gmtoff=-21600
/usr/share/zoneinfo/MST7MDT  Sun Nov  4 07:59:59 2007 UTC = Sun Nov  4 
01:59:59 2007 MDT isdst=1 gmtoff=-21600
/usr/share/zoneinfo/MST7MDT  Sun Nov  4 08:00:00 2007 UTC = Sun Nov  4 
01:00:00 2007 MST isdst=0 gmtoff=-25200
--------
Note the assignments of UTC to MST.  The two sets of results
differ by an hour, but "gmtoff" is unchanged.

I assume that Linux basically ignores local time, and runs all its time
services off of UTC.  If that's not true, then things might be really
interesting. :-)

Anyone have better insight into this?

--Rick Kwan