Using TZEdit on Windows SP, SP2, SP3 for daylight saving time (DST)

If you’ve got some older systems or a new netbook that can’t quite handle Vista , you might be hanging onto Windows XP longer than you thought. 

Out of the box, XP and the new DST changes don’t get along. 

As a result of The U.S. Energy Policy Act of 2005, the United States has an extended daylight saving period that lasts 3-4 weeks longer than in years prior to 2007. 

But there’s a fix!

There’s a handful of ways to update your computer so that it supports the new DST dates:

  • Downloading an EXE update
  • Manual registry changes
  • TZEdit and some others…

For a single machine, I found the most straight-forward way to update your machine is through TZEdit.

  1. Download TZEdit.
  2. Run TZEdit.exe to extract it to the default directory (C:\Program Files\TZEDIT).
  3. Run C:\Program Files\TZEDIT\TZEdit.exe.
  4. The timezone configured on your machine should be automatically selected.
  5. Click the Edit button.
  6. Change the Start Day to the Second Sunday of March at 2:00am.
  7. Change the Last Day to the First Sunday of November at 2:00am.
  8. Click OK.
  9. I found to get the settings to stick I had to change time zones in the Date and Time Properties window (the window that pops up when you double-click the time in the tray).  Change to some other time zone, and then change back to your original time zone.
  10. Now reboot.
  11. To test, change your date/time to the second Sunday of March at 1:59:59am.  If all went well, you should “spring” forward to 3:00am.

If you’d like more technical information on more advanced configuration, jump over to Microsoft’s Help Page.

About the Author

Ray Li

Ray is a software engineer and data enthusiast who has been blogging for over a decade. He loves to learn, teach and grow. You’ll usually find him wrangling data, programming and lifehacking.

Comments 1

  1. Avatar

    very helpful, I used TXEDIT.exe but didn’t help cause I didn’t change time zone to some other and back, that’s the main point

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