About Daylight Savings Time
The change in U.S. practice regarding Daylight Savings Time (DST) affects SDS products as follows:
VIP and VSV Servers rely on Java virtual machines (JVMs). JVMs programmed before August 2005, when the new U.S. DST law was written, will report incorrect U.S. times for 4 weeks each year—3 weeks in late March and 1 in early November.
JVMs are a part of Java Software Development Kits (SDKs). To avoid time problems, update the Java SDKs on the host machines where VSV and VIP servers reside.
The IBM USS platform; IBM SDKs
The USS platform uses the Java SDK provided by IBM. Other platforms may also use SDKs from IBM, but that is less common. To learn about DST changes in IBM’s Java SDK see www-1.ibm.com/support /docview.wss? &uid=swg21251761.
Linux, Unix, and Windows platforms; Sun SDKs
Platforms other than IBM’s typically use Java SDKs provided by Sun Microsystems. To learn which versions of the Sun SDKs recognize the new DST rules, see java.sun.com /developer /technicalArticles /Intl/USDST/
The new Daylight Savings Time
Starting in 2007, U.S. DST runs from the 2nd Sunday of March to the 1st Sunday of November. Previously, U.S. DST went from the 1st Sunday of April to the last Sunday of October.
At 2:00 a.m. on March 11, U.S. clocks will re-set to 3:00 a.m. According to those clocks, the sun will rise and set an hour later than on March 10. At 2:00 a.m. on November 4, the clocks will revert to 1:00 a.m.
U.S. DST does not apply in the state of Hawaii, or in the state of Arizona outside of the Navajo Reservation. The new dates for U.S. DST also apply in Canada, Bermuda, and the Bahamas. Changes to DST have also taken place recently in Brazil and Australia.
Browsers and their Java Plug-Ins (JREs)
Incorrect clocks at client machines and their web browsers will not affect SDS products. The following is provided as a convenience to our customers.
Web browsers typically read time from their host machines via JavaScript code. Web pages may also use Java Applets, which get time from the JVM incorporated into a browser’s Java plug-in, a.k.a. its Java Runtime Engine (JRE).
Both sources will report incorrect time if the host machine’s operating system has the incorrect time. In addition, JREs that are too old to know the new DST rules may make adjust for DST incorrectly.
For more information about JREs and DST, see java.sun.com /developer /technicalArticles /Intl/USDST/