[ANN] Major Windows DST Bug

[Devin Asay]

On Mar 12, 2007, at 3:06 PM, Ken Ray wrote:

> I have uncovered a Major (BLOCKER) Windows bug related to the most
> recent change in Daylight Savings Time for the United States.
> Revolution will overcompensate for the DST by adding and additional
> hour to the time whenever you execute 'convert'. To see what I mean,
> make sure you have "Automatically adjust clock for Daylight Savings
> Time" turned on in your Date/Time prefs, launch Rev (or MC) under at
> least XP Pro or Vista Home Premium (the two systems I tested), and  
> type:
>
>   put the time into x;convert x to long time;put x
>
> You should see that the time you get back is one more hour ahead of
> your current time. So if it is currently 2:05 PM without the DST
> adjustment, and you have the checkbox checked, Windows will show that
> it is 3:05 PM (correct). But if you run the code above, x will be
> "4:05:00 PM".
>
> I can only assume that when Rev asks the OS for the time it gets two
> factors the non-adjusted time, and a flag whether DST is currently
> applied. In the past, Windows would have handed over "2:05" and "True"
> (in the example above), and Rev would have adjusted the time
> accordingly. But the latest Windows XP/Vista DST patch seems to be
> handing over the ADJUSTED time, and the flag, so it would hand over
> "3:05" and "True", so Rev is over-adjusting by another hour.
>
> There is no easy scripted fix other than finding every location where
> 'convert' is used and parsing strings into chunks.... yechh!
>
> I have logged this into Bugzilla as bug #4526.
>
> This is a MAJOR BLOCKER problem and is going to hit a LOT of  
> people, so
> forwarned is forearmed...

Talk about timing! I was just this minute debugging a Rev-based  
scheduling app that is working fine on my Mac, but on XP the time  
returned when I request a certain time on the schedule are *2 hours  
ahead* of what they should be. (I have the "Automatically adjust"  
flag set to true in Windows.) Oy! I use convert heavily in this app,  
too.

This seems like a problem with the windows DST patch, not Rev. So  
shouldn't Microsoft fix it? Surely Rev isn't the only application  
affected by it.

Devin


Devin Asay
Humanities Technology and Research Support Center
Brigham Young University