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ballu · Site Admin Joined: 17 Jan 2007 Posts: 34 Location: INDIA

Daylight Saving Time updates to Linux operating systems for year 2007

Red Hat updates are available for the following current releases:
Affected Products:

Red Hat Desktop (v. 3)
Red Hat Desktop (v. 4)
Red Hat Enterprise Linux AS (v. 3)
Red Hat Enterprise Linux AS (v. 4)
Red Hat Enterprise Linux ES (v. 3)
Red Hat Enterprise Linux ES (v. 4)
Red Hat Enterprise Linux WS (v. 3)
Red Hat Enterprise Linux WS (v. 4)

This involves an update to:

RHEL 2.1 -> glibc of at least level glibc-2.2.4-32.23

RHEL 3 & 4 -> tzdata of at least level tzdata-2006m-1.EL3 or tzdata-2006m-1.EL4 respectively.

To prepare older Linux systems for 2007 DST change:

1) Download and install the latest tzdata rpm:

# rpm -u tzdata-2006m-3.el4.noarch.rpm

2) In order for the change to be effective, you need to copy over the /etc/localtime

# zdump -v /etc/localtime | grep 2007
/etc/localtime Sun Apr 1 06:59:59 2007 UTC = Sun Apr 1 01:59:59 2007 EST isdst=0 gmtoff=-18000
/etc/localtime Sun Apr 1 07:00:00 2007 UTC = Sun Apr 1 03:00:00 2007 EDT isdst=1 gmtoff=-14400
/etc/localtime Sun Oct 28 05:59:59 2007 UTC = Sun Oct 28 01:59:59 2007 EDT isdst=1 gmtoff=-14400
/etc/localtime Sun Oct 28 06:00:00 2007 UTC = Sun Oct 28 01:00:00 2007 EST isdst=0 gmtoff=-18000

# cp /usr/share/zoneinfo/America/New_York /etc/localtime

# zdump -v /etc/localtime | grep 2007
/etc/localtime Sun Mar 11 06:59:59 2007 UTC = Sun Mar 11 01:59:59 2007 EST isdst=0 gmtoff=-18000
/etc/localtime Sun Mar 11 07:00:00 2007 UTC = Sun Mar 11 03:00:00 2007 EDT isdst=1 gmtoff=-14400
/etc/localtime Sun Nov 4 05:59:59 2007 UTC = Sun Nov 4 01:59:59 2007 EDT isdst=1 gmtoff=-14400
/etc/localtime Sun Nov 4 06:00:00 2007 UTC = Sun Nov 4 01:00:00 2007 EST isdst=0 gmtoff=-18000

Also search you system for any application have their own copy of localtime and update those if needed:
# find / -name localtime -ls

OR

To be safe, simply reboot your server and this will ensure all applications will use the DST changes.
#rpm -u tzdata-2006m-3.el4.noarch.rpm; reboot

To verify if your server will be ready for the new DST time changes in 2007
# zdump -v EST5EDT | grep 2007
# zdump -v CST6CDT | grep 2007
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Regards
Bala