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'Daylight Savings Bugs' Loom
An anonymous reader writes "ZDNet has front page coverage of the looming daylight savings changeover, and the bugs that may crop up this year. With the extension of daylight savings time by four weeks, some engineers and programmers are warning that unprepared companies will experience serious problems in March. While companies like Microsoft have already patched their software, Gartner is warning that bugs in the travel and banking sectors could have unforeseen consequences in the coming months. ' In addition, trading applications might execute purchases and sales at the wrong time, and cell phone-billing software could charge peak rates at off-peak hours. On top of that, the effect is expected to be felt around the world: Canada and Bermuda are conforming to the U.S.-mandated change, and time zone shifts have happened in other locales as well.'" Is this just more Y2K doomsaying, or do you think there's a serious problem here?
http://www.bloomingtonlinux.org/wiki/DST_Time_Chan ge_Issues
A year ago, after most of Indiana went through its first timezone change in 40+ years, we found out that it presented a few problems in Linux, I tried to post a story to Slashdot about it to warn other people in the US that they would be dealing with this problem later when the rest of the US changes to the new DST. I tried several times to post it and they were all rejected.
Basically, you need to make sure that if you change your timezone data on your system that you restart everything, otherwise when the time does change, some programs continue to use the old timezone data and are an hour off.
... On how to deal with this is below:
http://www.reganfamily.ca/dst/
This is likely more useful than the original article. It has resources for everything from Blackberries to UNIX.
This is my opinion. To make sure you don't steal it, it's covered by the DMCA.
Ahem, not exactly. No patch for the perfectly good Exchange 5.5 server we're using with Outlook 2000. Suddenly we have to update to the latest Exchange and Outlook 2003 on every d@mn desktop. And I'm in Arizona were we don't even have daylight savings time!!!
"It's the height of ridiculousness to say for those 9 lines you get hundreds of millions."
The tz database http://www.twinsun.com/tz/tz-link.htm underlies time zone handling for the GNU C Library, FreeBSD, NetBSD, OpenBSD, Mac OS X, Solaris and many more, and is kept current by a dedicated team of (mostly?) volunteers. For time nerds, the historical comments in the plain text files of the tz ftp distribution (ftp://elsie.nci.nih.gov/pub/tzdata2007b.tar.gz) are required reading.
If you're a Firefox person, FoxClocks (see my URL above) puts nice little world clocks on your statusbar. And yes, it uses tz too. Thanks guys. Andy
We have literally hundreds of servers running Windows 2000, and this DST patch was a major headache. As the parent noted, Microsoft did not include Win2K in their publicly released update.
There is a freeware utility to apply the DST patch on Win2K machines here (as a bonus, it also supports WinNT).
Note that you may also need to update the Java JRE/JDK.
Apple just pushed an update through Software Update that fixes potential daylight saving time problems. You can grab it here if you use Tiger, or here if you still use Panther. It also released a similar update for Java. here is the Tiger version and here is the Panther one.
"Words of wisdom: drop that zero and get with the hero" -- Vanilla Ice
The DST thing is pretty evil too because it's usually up to runtime stacks like Java and CRT to decide on the timezone and time. If they give you the wrong time you're screwed. For the most part you might be okay if everything resolves down to some registry entries or timezone data files but that isn't always the case. There are functions such as Microsoft's _tzset() which are HARDCODED to a particular behaviour and apps that link to the CRT or have their own DLLs will be broken unless you recompile them.
% zdump -v /etc/localtime| grep 2007 /etc/localtime Sun Mar 11 09:59:59 2007 UTC = Sun Mar 11 01:59:59 2007 PST isdst=0 gmtoff=-28800 /etc/localtime Sun Mar 11 10:00:00 2007 UTC = Sun Mar 11 03:00:00 2007 PDT isdst=1 gmtoff=-25200 /etc/localtime Sun Nov 4 08:59:59 2007 UTC = Sun Nov 4 01:59:59 2007 PDT isdst=1 gmtoff=-25200 /etc/localtime Sun Nov 4 09:00:00 2007 UTC = Sun Nov 4 01:00:00 2007 PST isdst=0 gmtoff=-28800
/etc/localtime is a symbolic link to the default timezone for your machine. (users can run their own timezone with the TZ environment variable).
/etc/localtime /etc/localtime -> /usr/share/zoneinfo/US/Pacific
notice that the isdst changes from 0 to 1 on March 11. This means I have the correct zoneinfo file in my system.
% ls -l
lrwxrwxrwx 1 root root 30 2006-09-24 21:50
PS - likely the steps to check this on FreeBSD are similar. Post your experiences.
“Common sense is not so common.” — Voltaire
> date --date="Mar 10 15:00:00 UTC 2007"
Sat Mar 10 10:00:00 EST 2007
> date --date="Mar 11 15:00:00 UTC 2007"
Sun Mar 11 11:00:00 EDT 2007
This won't set your clock or anything, it just does the timezone conversion from UTC and displays the results according to the local timezone you have selected.