As you are likely aware, the dates on which daylight saving time begins and ends are changing as of 2007. Daylight saving time in Ontario will follow the new dates used in the U.S., so it will begin on the second Sunday in March and continue until the first Sunday in November.
Modern operating systems, and some applications, need to know about the rules determining when DST begins and ends. Most of the software currently in use was written prior to the recent change, and so it will not calculate these dates correctly without an update being applied. Since software often has to be able to calculate dates and times for some distance into the future (for example, if you make a calendar entry for an upcoming meeting), these updates should be applied sooner rather than later.
To assist you, we have compiled a list with information for a number of affected products which are used by many of our clients. However, we would stress that the definitive source of information is the vendor of the software, so please make sure that you visit the vendor's Web site (we have provided links in many cases) for complete information.
Microsoft has a master page with links to the relevant information for their products: http://support.microsoft.com/gp/dst
As well, there is table at http://www.microsoft.com/windows/timezone/dst2007.mspx listing what, if anything, needs to be done to each version of Windows (and to other Microsoft software).
NetWare 4 and above uses console SET parameters to determine the start and end dates for DST. These can be edited manually. Novell has also released a utility, DSTSHIFT, which will make these changes automatically on most versions of NetWare. See this page for full details.
OpenServer 5.0.7's DST rules are adjusted by applying Maintenance Pack 5. Older versions of OpenServer 5 will require manual adjustment of the TZ environment variable to specify the new DST rules. The man page for timezone (F) describes how to construct the rules, and the man page for tz (M) describes how to set them.
To implement the new rules for the Eastern timezone, you would set the TZ environment variable to the following value:
EST5EDT,M3.2.0,M11.1.0
This would normally be done in the file /etc/TIMEZONE, but you should examine your system to ensure that it is not listed anywhere else. Some processes may not recognize this change until the system is rebooted, so it would be wise to reboot the server in advance of the start of DST.
Red Hat has a master page with information on what needs to be done to their products to implement the new DST rules: http://kbase.redhat.com/faq/FAQ_80_7909.shtm
Lotus has a master page with links to the relevant information for their products: http://www-1.ibm.com/support/docview.wss?rs=899&uid=swg21245334
Sun has a master page with information regarding which versions of their Java environments include the updated DST rules: http://java.sun.com/developer/technicalArticles/Intl/USDST/index.html
Basically, recent releases of the Java Runtime Environment include the updated DST rules. If you have been keeping your machines up to date with JRE updates, you have the latest rules. If you have not, you should, as there have been a number of bugs (including some security bugs) fixed by JRE updates.
RIM has a page with information and links to updates to implement the DST changes: http://www.blackberry.com/select/dst2007/
Back to list of newsletters