(No "clock" subcategory of "computer", so this "timer" subcategory will have to do.)

Have you ever been using your computer at 2:00am when the Daylight Savings Time adjustment is automatically performed by your computer? In the autumn, clocks are supposed to be set back one hour, so now your computer time is 1:00am.

So you keep working, and a hour later it is 2:00am again.

The stupid computer does another time adjustment!!!!

It needs to remember that it DID the adjustment, just to prevent this stupidity!
-- Vernon, Nov 08 2010

"Do You Know What Time It Is?" http://www.bbc.co.uk/programmes/b00fyl5z
A rather entertaining BBC program about the nature of time. [DrBob, Nov 09 2010]

Also baked - I have a number of computers here that always adjust themselves correctly.
-- pocmloc, Nov 08 2010


The Borg are always well adjusted.
-- 8th of 7, Nov 08 2010


It works fine for me too, on at least four different computers.

"Widely known to exist"?
-- Wrongfellow, Nov 08 2010


Never seen this happen, all computers I use know to do only a single adjustment.
-- MechE, Nov 08 2010


//That an Apple thing?//
iPhone alarms are all going off an hour later than they are supposed to due to a DST problem in iOS4.1

Isn't it amazing how even the most fundamental of questions (e.g. What time is it?) still provide tricky problems!

But, Vernon, a proper implementation of any DST algorithm should be something along the lines of having a flag that says "is it DST or not?" if the flag is set, then it is DST, if not, then it's not. And if the flag is set, then the time is [local-time]-1 hour. That way, you can only set the flag once, any subsequent setting falls on deaf-ears (or the equivalent in electronic flag-terms).
-- zen_tom, Nov 08 2010


<insert argument for computers telling time internally as GMT>
-- FlyingToaster, Nov 08 2010


[FT] I thought they all told time in seconds since The Epoch.
-- mouseposture, Nov 09 2010


Folks, the computer that I've most often seen this problem, over the years, is a Windows 95 machine. I can't recall using some other computer during the autumnal 2am DST adjustment.

One way to test this on any other computer, though, is simply lie about the date/time (manually set it so that it is about to do the autumnal adjustment), and then see what happens an hour after it does the adjustment, leaving the computer on the whole time.

[hippo], your MFD is invalid. The computer DOES do a DST adjustment, so "it works". The problem is, it works more than it should!
-- Vernon, Nov 09 2010



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