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<p>This is a summary of the information about the change in Daylight
Savings Time rules and how the change affects FreeBSD releases.</p>

<p>In 2005 several countries, including the United States of America
and Canada, passed legislation changing when Daylight Savings Time
begins and ends.  That change takes effect in 2007.  For the time
zones affected by the change Daylight Savings Time will begin on
March 11th (instead of April 1st) and end on November 4th (instead
of October 28th).</p>

<p>FreeBSD uses <tt>/etc/localtime</tt> to control the conversion of
the system's internal representation of time (based on UTC) to the
format appropriate for the local time zone.  That file gets
copied from one of the files in <tt>/usr/share/zoneinfo</tt> by the
tzsetup(8) command, usually as part of the initial installation
procedure.  The change in Daylight Savings Time rules affects the
files in <tt>/usr/share/zoneinfo</tt> for the time zones affected by
the legislation passed in 2005.</p>

<p>Of the release branches supported by the FreeBSD Security Team
as of February 2007, FreeBSD-6.2 and FreeBSD-5.5 have up to date
zoneinfo files.  FreeBSD-6.1 has correct zoneinfo files for
time zones in the United States of America but out of date
zoneinfo files for some of the other countries affected (for
example Canada).  An Errata Notice will be released shortly
to update the zoneinfo files in FreeBSD-6.1.</p>

<p>For the development branches HEAD, RELENG_6, RELENG_5, and
RELENG_4 all have the correct zoneinfo files in them.</p>

<p>NOTE: <tt>/etc/localtime</tt> currently does not get updated when
the cvsup/buildworld/etc system update procedures are used.  If a machine
was installed using one of the releases not listed above it will
probably have an outdated <tt>/etc/localtime</tt> file.  That file can
be updated by running tzsetup(8).</p>

<p>For older systems no longer under support the misc/zoneinfo
port can be installed to update the <tt>/usr/share/zoneinfo</tt> files,
followed by running tzsetup(8) to update <tt>/etc/localtime</tt>.</p>

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