[MD1] HFS+ and Daylight savings

[MD1] HFS+ and Daylight savings

From: MWRon@metrowerks.com (MW Ron)
Subject: Daylight Savings Time & Mac OS Extended Volumes

Projects built with CodeWarrior that are stored on a HFS+ volume will be
rebuilt after Daylight savings time is changed.......

(http://til.info.apple.com/techinfo.nsf/artnum/n24452)

TITLE
Mac OS 8.1: Daylight Savings Time & Mac OS Extended Volumes

TOPIC
I notice that when I check Daylight Saving Time in the Date & Time control
panel, both the creation and modification times of files on a Mac OS
Extended volume change by one hour.If I change the time by hand, the times
do not change. Times on HFS volumes don't change either. What is going on?

DISCUSSION
The reason the times change is that Mac OS Extended stores the creation and
modification times in GMT time. The offset from GMT is stored in PRAM. This
value is added to the time stored for the file to determine the correct
creation or modification time.The GMT offset is stored when you select a
time zone in the Date & Time control panel. This offset is modified when
Daylight Saving Time is checked. Since the value is stored as seconds, 3600
is either added to or subtracted from the GMT offset depending upon whether
entering or exiting Daylight Saving Time, respectively.For example, a file
was created at 12:00 PM Pacific Standard Time. The value stored was 8:00 PM
GMT since there is an 8 hour difference. When Daylight Saving Time is in
effect, the difference is only 7 hours. This causes the creation time of
the file to be displayed as 1:00 PM PST, not 12:00 PM.Changing time zones
will also affect the creation and modification dates.Drawbacks of this are
that aliases may break and incremental backups may become full backups
since every file appears to have been modified.

 
AAPL
$282.52
Apple Inc.
-1.23
MSFT
$24.38
Microsoft Corpora
-0.11
GOOG
$525.62
Google Inc.
-0.17
MacTech Search:
Community Search:

Introducing the App Hall of Fame!
App discoverability continues to be a real issue. With the fast churn of apps in the App Store, an app has only a few weeks of promotional life in it before it‚Äôs largely forgotten. There are a few things developers can do to fix that, but those... | Read more »
Gobliiins Are Coming
In the midst of the huge Q4 launch schedule, the cult classic, Gobliiins, as well as the rest of the trilogy, are being ported to the iPhone in all of their original glory. The Goblins trilogy was a quirky Atari/Amiga game series from the early 90‚Äôs... | Read more »
myPhoneDesktop – Chrome to iPhone Extens...
Anyone who has used myPhoneDesktop knows that it is a fantastic tool for streamlining your onscreen workflow. Instead of having to type line after line into your phone directly, you can use myPhoneDesktop to type from your computer directly into... | Read more »
Classes Review
Developer: Dustlab Price: $0.99 Version Reviewed: 2.4.7 iPhone Integration Rating: 3 out of 5 stars User Interface Rating: 4 out of 5 stars Re-use / Replay Value Rating: 3 out of 5 stars Overall Rating: 3.33 out of 5 stars | Read more »
AutoVerbal Talking Soundboard Pro helps...
Being able to speak and communicate with others is something that many of us take for granted. It‚Äôs not so easy for many folks though, in particular for individuals with autism spectrum disorders, as well as those who have suffered various brain... | Read more »
Pocketbooth Review
Developer: Project Box Price: $0.99 Version Reviewed: 1.0 iPhone Integration Rating: 4 out of 5 stars User Interface Rating: 4 out of 5 stars Re-use / Replay Value Rating: 4.5 out of 5 stars Overall Rating: 4.17 out of 5 stars | Read more »
Get Your Roast Right With ‘Time To Roast...
Roasting meat, in the cooking world, is about as simple as it gets. The greatest roast recipe I‚Äôve ever found is from Michael Ruhlman‚Äôs website, with the recipe titled, ‚ÄúThe World‚Äôs Most Difficult Roasted Chicken Recipe.‚Äù | Read more »

All contents are Copyright 1984-2010 by Xplain Corporation. All rights reserved. Theme designed by Icreon.
Greetings, and welcome to the new MacTech web site! Our home page is designed to be your Industry Dashboard -- so you can have a snapshot of all that's relevant in the industry in one easy location. Many readers tell us that because the information is updated so frequently, they are now checking the site multiple times a day. Here's a quick run down of the features on the new web site, which can be subtle. We truly hope you register so that we can keep you up to date about new features as they are implemented. And, please use the BETA button in the top right to provide us any feedback, suggestions or bugs. We love to hear from you.