The day after the clocks changed, I was teaching the Mindsharp Upgrade course, in Finland at FC Sovelto for Combined-Knowledge. I had read about the DST (Daylight Saving Time) fixes, but as our virtual machines use GMT then they are not applicable. However, all the upgrade labs were taking an hour longer to complete. As a class we recognized that this could have something to do with DST and on searching the Internet found, Darrin's post, "Daylight Savings Time Strikes Back!" and the KB 932563, "One-time timer jobs will not run until one hour after the jobs were created in SharePoint Server 2007".
On the first server in the farm, the SharePoint Products and Technologies Wizard, schedules a timer job. Usually this remains in a status of Pending for a short time, before it starts the timer jobs that will sequentially upgrade the SharePoint installation. However with the advent of DST, the timer job remains in a pending status for an hour. So prior to DST, depending on the power of the student's computers, the upgrade exercises would take somewhere between 30-45 minutes, but after DST they take 90-105 minutes. This problem affects all upgrade scenarios - Window SharePoint Services 2.0 to Windows SharePoint Services 3.0 and SharePoint Portal Server 2003 to Microsoft SharePoint Server 2007.
I've done a little testing and on the Date and Time Properties dialog box, on the Time Zone tab, if the Automatically adjust clock for daylight saving changes check box is cleared, then have the hour delay in the SharePoint timer job. This may be an alternative to waiting until the official Microsoft fix is available or changing the timezone of your servers. See Stefan's post, "MOSS timer jobs delayed by one hour if system regional settings are configured for DST "as to which timezone to choose.
Please check that this does not adversely affect your implementation, for example, I don't know if I'd do this on a domain controller.