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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.
The reason y2k was such a letdown was because everybody took heed of the media hype and patched their stuff. If there had been no hype before, there might have been the problems that the hype was warning about. (or not, sensationalism is sensationalism)
Its like you're driving along and there's a huge backup for miles because of an accident in the middle of the road after a bend. Now this huge backup may have slowed you down and made you aware that there was a problem. If it was just you and the wreck, you may have plowed into it if you weren't paying attention.
Same thing with this hype. We should tolerate the hype because the heightened coverage will get bosses talking to programmers about fixing the software, and it'll turn out to be nothing.
Is it sad that I am more likely to recognize you and your posts by your sig than your name or UID?
and cell phone-billing software could charge peak rates at off-peak hours
Aiyeeee!!!!!!!!!!!!!
... 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."
And I thought that the year 1906 would pass with out any issues.
I don't see anyone saying planes are going to fall out of the sky or anything like that. Trades could be executed at the wrong time, costing people money. Cell phones could charge peak rates at the wrong times, costing people money. These could very easily happen if these companies were not on the ball about getting this patched early. Luckily, most operating systems required a simple patch (sometimes a reboot) to fix this, and that's about it. The extensive code fixes that the Y2K bug required simply aren't necessary here.
However, because of the perceived simplicity of the fix, there is a real possibility that some companies waited too late to address the issue and may not make it in time. This may cause minor glitches, but it's not like the nukes are going to start flying.
As for Y2K, obviously the people who were stockpiling ammunition and moving to the mountains were nuts, but there were real problems that could have occurred that did not because of the countless hours that were put in to fix the issues. It drives me crazy that after we spent millions of dollars and countless man hours fixing buggy code for Y2K, people look back and see that nothing happened and think all that money was a waste. If all that effort had not been expended, more computer systems would have had problems, and so the money was definitely not wasted. During Y2K, there were scattered reports of various computer systems crashing. It is likely there would have been many more such reports had we not taken the steps we did to address the issue.
Newer JDK's already have the new time zone rules encoded, and this can cause subtle bugs to suddenly surface. It turns out that Date.equals() does a deep object compare, including the time zone rules (not just which time zone you're in, but the rules regarding when daylight savings starts and ends). Thus if you have multiple JVMs involved, such as one on a database server and one on an application server running slightly different JVM revs (e.g. 1.4.2_08 vs. 1.4.2_11), then naive date comparisons (using equals() instead of equality on getTime()) can fail.
It serves no useful purpose any longer in what is almost a 24 hour society. What difference does it make to the vast majority of people what time the sun rises and sets anymore? All it does is add a small extra layer of confusion and complexity thats no longer necessary? If people really don't want to get up when its dark then go to work an hour later and leave an hour later. With flexitime its really not an issue anymore.
Think of how many companies have old systems that just continue to run forever. Most OS vendors drop OS patch support after about 5 years.
Okay, so all system processes should use UTC. We all know that. Users don't set their watches to UTC though.
Want a DST patch for Solaris 8? RHAS 2.1? Windows NT? You're going to have to shuffle and maybe you'll need to update the timezone files with 'zic' yourself. Have hundreds or thousands of these machines. Sucks to be you.
Oh, and the big killer is that Java has timezone rules embedded in it. That's right. Java VIRTUAL MACHINE. Java tracks timezones and DST changes INDEPENDENT of the OS since Java wants to be it's own OS.
So, if your company standardized on j2ee when you moved off the legacy systems for y2k, I'll almost bet you that the OS those java apps are running on won't have DST patches from the vendor, and your apps could have multiple JVMs that contain the wrong DST rules. You'll need to fix both of those if your java apps have anything to do with timezones and if you care about the times displayed.
I'd really like to get a list of everyone who voted for the 2005 dst timezone changes and start a movement to make them take responsibility for the huge business cost of their stupid legislation. It has to be 100X the cost of what they expected the changes to save...
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
This is worse than Y2K because Java needs to be patched, and JVMs proliferate on hosts like cockroaches. Older JVMs cannot be patched.
There are nearly 50 java instances on some of our hosts. The filthy little bastards hide everywhere.
Fortunately the fix can be automated and is very fast to install.
Using java's extensive built-in patch management and version management capabilities, of course.
Give a man a fish and you have fed him for today. Teach a man to fish, and he'll say "WHERE'S MY FISH, YOU IDIOT?"
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.
You'll catch up to the rest of us in three weeks!
If "disco" means "I learn" in Latin, does "discothèque" mean "I learn technology"?
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
i recognize the interest in giving people more daylight hours for harvest/ farming purposes... and how that's still nice in a service/ industrial work setting to have barbeque time after work
but why does that mean that time has to be shifted twice every year? why not just shift time by an hour once, just one time, and be done with the nonsense forever? why is it necessary to go back to "real" time in the winter?
heck, sometimes i think we should redefine 6 am as 3 am. then everyone wakes up and goes to work in the middle of the "night", and, after work in the summer, you have daylight until midnight!
we're dealing with an abstract concept here. we can do whatever we want with time. we don't have to abide by some weird need to swithc back to "real" time in the winter. just shift it once in favor of farmers/ after work barbequers and be gone with it. it's just so stupid and pointless and a waste of effort to constantly shift back and forth
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
Everything is fine in Australia? Remember folks, this announcement is coming from the country that gave us The Wiggles.
% 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
Let's switch to the metric system while we're at it.
"In no way were dates routinely stored as two byte characters (99 being the max) when 1 byte would get you to 255 easily." Wrong. In EVERY WAY dates were routinely stored as three sets of two byte characters.
What you are completely ignoring is that the vast majority of the code that had to be examined and patched was written in COBOL. COBOL that store dates as a string of six digits. Digits that were stored in many cases as EBCDIC characters, not hexadecimal integer values. And just to make it fun, in some cases the source code was not available.
"[A]nyone that created a four digit date by String Concat: "19" + String(date) would " probably not have been born yet when the programs that needed to be fixed were written. It wasn't the programs that were written in the 1990's that had to be dealt with, it was the ones written in the 1960's. And if you don't believe there were any of those in use, then I suggest you have no idea what's really happening at your bank. Or in the US air traffic control system, for that matter.
Slightly disreputable, albeit gregarious
Why does Windows not run UTC on the CMOS clock? Doing so would solve all of this "The computer has changed the clock" twice a year. The clock wouldn't be changed, just synced every now and then, but the displayed time would automatically be adjusted. POSIX and MacOS does this correctly, and 99.99% of Mac users don't even realize their CMOS clock runs UTC. Changing Daylight Time would be updating a single file, even in a closed OS like windows.
I've heard all sorts of dumb reasons against running UTC on the CMOS, like "who cares about UTC, My time is local" and "why should I keep two different times on my computer".
But, the OS will hide the UTC from you, and besides, when was the last time you used the BIOS time as your clock?
Forcing UTC on the CMOS clock is surprising since WindowsNT has used UTC for all their internal time tracking for some time. But they *calculate* it from local time, which changes twice a year, _even though_ Windows uses NTP time servers. Doh. It's gotta be *the* dumbest backward compatibility "feature". See here: http://www.cl.cam.ac.uk/~mgk25/mswish/ut-rtc.html
In Soviet Russia, articles before post read *you*!
> 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.
Where I worked, we had a lot of old but reliable systems. We tested our mainframes, minicomputers, PCs, and network systems - they failed in varying and catastrophic ways.
We spent millions of dollars for all new systems, and thousands of hours in planning, procurement, implementation, and testing. We literally pushed all the boxes on the datacenter floor to the wall and built anew.
It was a horrendous chore, and I didn't get to spend New Year's with my family.
Perhaps we should have let you all freeze in the dark.
You can't talk about Wikipedia's flaws on Wikipedia