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Subject: [FreeBSD-Announce] FreeBSD Errata Notice FreeBSD-EN-07:04.zoneinfo
From: FreeBSD Errata Notices <This email address is being protected from spambots. You need JavaScript enabled to view it.>
Date: Wed, 28 Feb 2007 18:49:37 GMT

Hash: SHA1

FreeBSD-EN-07:04.zoneinfo                                       Errata Notice
                                                          The FreeBSD Project

Topic:		Zoneinfo file update

Category:       core
Module:         share_zoneinfo
Announced:      2007-02-28
Affects:        FreeBSD 6.1-RELEASE
Corrected:      2007-02-28 18:23:09 UTC (RELENG_6_1, 6.1-RELEASE-p15)

For general information regarding FreeBSD Errata Notices and Security
Advisories, including descriptions of the fields above, security
branches, and the following sections, please visit

I.   Background

The tzsetup(8) program allows the user to specify the default local
timezone.  Based on the user's choice, tzsetup(8) copies one of the
files from /usr/share/zoneinfo to /etc/localtime.  This file actually
controls the conversion.

II.  Problem Description

In 2005 several governments, among them the United States of America and
Canada, decided to change when Daylight Savings Time begins and ends.
The change takes effect in 2007.  Because of that change the data in
the zoneinfo files needs to be updated, and if the computer's local
time zone is affected tzsetup(8) needs to be run so /etc/localtime
gets updated.

FreeBSD 6.1-RELEASE shipped with the correct zoneinfo files for the United
States time zones affected by the change made in 2005, but the zoneinfo
files for several other countries (e.g. Canada) do not contain current

III. Impact

If the /usr/share/zoneinfo files as well as /etc/localtime are not updated
on a computer that has its time zone set to one of the regions affected by
the change made in 2005 it will display the wrong time between March 15th
and April 1st, then again between October 28th and November 4th.  All things
on that computer that rely on the system time (e.g. cron jobs, timestamps
entered in log files, etc) will be affected.

IV.  Workaround

At least in theory the system time could be manually adjusted by an hour
on the affected dates.  However the system will still incorrectly say whether
or not Daylight Savings Time is in effect (e.g. it will still say the
time is "EST" instead of "EDT" for the Eastern US).  Doing this is NOT
recommended because the kernel stores timestamp information in the
filesystem and other places using its internal representation of time
(based on UTC).

Since the following is such a frequently asked question we will mention
the answer here.  Using an NTP server as the source of your system's
time will NOT automatically take care of the change in Daylight Savings
Time.  This patch should still be applied if you are in a region that
is affected.

V.   Solution

Following the instructions in this Errata Notice will update all of
the zoneinfo files to be the same as what was released with FreeBSD

Perform one of the following:

1) Upgrade your affected system to 6-STABLE or to the RELENG_6_1
security branch dated after the correction date.

2) To patch your present system:

The following patches have been verified to apply to FreeBSD 6.1

a) Download the relevant patch from the location below, and verify the
detached PGP signature using your PGP utility.

# fetch
# fetch

b) Execute the following commands as root:

# cd /usr/src
# patch < /path/to/patch
# cd /usr/src/share/misc
# make obj && make depend && make && make install
# cd /usr/src/share/zoneinfo
# make obj && make depend && make && make install
# tzsetup

VI.  Correction details

The following list contains the revision numbers of each file that was
corrected in FreeBSD.

Branch                                                           Revision
- -------------------------------------------------------------------------
  src/UPDATING                                            1.416.
- -------------------------------------------------------------------------

The latest revision of this Errata Notice is available at
Version: GnuPG v1.4.6 (FreeBSD)

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