First off, this guidance is not for the novice. If you're not sure about how to use certain tools or update your registry, think twice before you mess around with your operating system files or manually configuring daylight saving time dates by modifying an existing time zone.
I have been pinged a couple of times by folks who have seen older versions of the Knowledge Base (KB) articles that are up on our web site that call for a certain utility previousl released in several resource kits:
"Where can I find Tzedit.exe to edit time zone info?"
We provided a tool that allows users to change the time zone settings on a single computer, cleverly referred to as the Time Zone Editor (aka Tzedit.exe). This tool lets you create and edit time zone entries for the date and time settings in Control Panel.
You can find Tzedit.exe available for download from the Microsoft Download Center here: Download the Tzedit.exe utility package.
In general, don't download Microsoft (or any other application for that matter) from an unknown third-party web site. Microsoft has scanned this file for viruses and stores the bits on security-enhanced servers that help prevent any unauthorized changes to the file.