NYCPHP Meetup

[nycphp-talk] PHP & Daylight Savings

Dave Youn jhy2104 at columbia.edu
Thu Jan 18 12:31:31 EST 2007


I just got this email, and thought it might be useful:


U.S. Energy Policy Act of 2005 implements the DST change for the U.S.
Beginning in March 2007, DST in the United States will begin on
the second Sunday in March and end on the first Sunday in November. DST
in 2007 begins March 11 and ends November 4. As a result, many countries
around the world have changed their daylight savings time (DST) dates
and their time zone definitions. This has a serious market impact on
Telecom, Financial, Airlines to name a few. Be aware that the government
will also be reviewing whether these DST changes actually saved energy
and may revise these dates next year.

As these changes go into effect, a failure to modify the system time
automatically may cause inaccurate system date and time which could lead
to unpredictable consequences depending on system usage. If systems
and/or software is not corrected for DST changes, they will report
incorrect time from 03/11/07 through 04/02/07 and from 10/29/07 through
11/04/07. (1 hour late and 1 hour early, respectively).

Be aware that even if you took steps to resolve the issues with the DST
change, you may need to reboot or restart your OS/Server/Application
after January 1, 2007 for the changes to go into effect.
--You may not need to reboot the OS, but applications that are time
aware will need to be restarted after the OS is patched.
--The SC firmware (1280/2900/3800/4800/4900/6800/6900) needs to be
rebooted for the DST changes to take place.
--Java has to be stopped before Java updates are installed or the
tzupdater tool is used

Affected systems:
1. Software affected:
--Solaris (all versions)
--Java
--Java Enterprise System (aka App Server, WebServer, Directory Server...)
--Development Kits
such as Sun Studio or Forte Developer.

2. Systems affected:
--Sun Fire Servers (1280/2900/3800/4800/4900/6800/6900)
--all other systems that use LOM use UTC for the timezone and are
unaffected by DST.
--For High end (12/15/20/25K), patch the SC just like a regular Solaris
system.

3. Storage:
--StorEdge T3/6120 understand DST.
--SE 3x1x (3310/3320/3510/3511). (This is still being confirmed).
--HDS ­ Customers are required to not set DST on HDS systems.

A few Sun Alerts to be aware of:
-Solaris (all versions):SunAlert 102178:Daylight Saving Time (DST)
Changes for Australia (2006), United States (2007) and Others.

-SunAlert 102754: Required C++ (Rogue Wave Tools.h++ library) Update
Needed For 2007 Daylight Saving Time Changes

- Systems: SunAlert 102617:Required Server Firmware for Timezone Changes
Due to U.S. Energy Policy Act of 2005.


With Regard to Java, Java Developer Kit, Java Virtual Machine Java
Run-time Environment
a) Solaris 8
--Ships with Java SE v1.1.8, v1.2.2, and v1.3.1 included in the Solaris
8 OE
--Applications dependent on v1.1.8 and v1.2.2 delivered in Solaris 8
will need to be
upgraded to a later Sun Java SE product family version.
--Applications dependent on v1.3.1 in Solaris 8 will need to be updated
to Java SE
v1.3.1_18 or later.

b)Solaris 9
--Ships with Java SE v1.2.2, and v1.4.2 included in the Solaris 9 OE
--Applications dependent on v1.2.2 delivered in Solaris 9 will need to
be upgraded to a
later Sun Java SE product family version.
--Applications dependent on v1.4.2 in Solaris 9 will need to be updated
to use v1.4.2_11
or later. Alternatively the Sun Timezone Update tool can be used on the
v1.4.2 installed
with/in Solaris 9.
Java, Java Developer Kit, Java Virtual Machine Java Run-time
Environment

c)Solaris 10
--Ships with Java SE v1.4.2 and 5.0 included in the Solaris 10 OE
--Applications dependent on v1.4.2 in Solaris 10 will need to be updated
to use v1.4.2_11
or later. Alternatively the Sun Timezone Update tool can be used on the
v1.4.2 installed
with/in Solaris 10.
--Applications dependent on Java SE 5.0 in Solaris 10 will need to be
updated to use 5.0
u6 or later. Alternatively the Sun Timezone Update tool can be used on
the 5.0 installed
with/in Solaris 10.

Java, Java Developer Kit, Java Virtual Machine Java Run-time
Environment
Recommendations:
--The following Java platform versions have correct time rules to handle
the DST
changes that will affect U.S. time zones in 2007:
--Java SE 6 or later
--J2SE 5.0 Update 6 or later
--J2SE 1.4.2_11 or later
--J2SE 1.3.1_18 or later
--For version 1.4 or later, you can also use a tool to modify the time
zone data within your
existing JRE. Get the "tzupdater" tool from the Java SE download page.
--Java Enterprise System: JES relies on JVM for time zone and DST
information. So updating Java will get the JES stack aware of the DST
changes



More comprehensive information -- periodically check these documents for
the latest updates:
--Big Admin Article - 2007 Daylight Saving Time Changes in the U.S.
http://www.sun.com/bigadmin/features/techtips/dst_changes.html

--U.S. Daylight Saving Time Changes in 2007
http://java.sun.com/developer/technicalArticles/Intl/USDST/

--US Daylight Savings Time Changes and the Java SE Platform:
http://java.sun.com/developer/technicalArticles/Intl/USDST_Faq.html

--Overview and Mitigation of the USA2007DST Issue for the Java SE
platform and Solaris OS
http://java.sun.com/developer/technicalArticles/Intl/USDST_Solaris.html

--JDK US DST Timezone Update Tool ­ 1.0
http://java.sun.com/javase/downloads/index.jsp

--JDK - US DST timezone 1.0.0
http://java.sun.com/javase/tzupdater_README.html

*****************************************
David Youn - Webmaster
Columbia University Medical Center
ph: 212.305.8891 212.305.1668 fax: 212.342.8499
http://www.cubhis.org/wds/





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