Consider the following scenario. You do the following on a computer that is running Microsoft Windows XP or Microsoft Windows Server 2003:
1. You install either the first or second version of the 2007 time zone update for Microsoft Windows operating systems that are documented in the following Microsoft Knowledge Base articles:
928388 - 2007 time zone update for Microsoft Windows operating systems
931836 - February 2007 cumulative time zone update for Microsoft Windows operating systems
2. You install the C run-time (CRT) update that is documented in the following Microsoft Knowledge Base article:
932590 - FIX: Windows-based applications that use the TZ environment variable may not work as expected because of changes to DST
3. You set the TZ environment variable.
*In this scenario, when you create a custom application that uses the Microsoft JScript Date object, the time is reported incorrectly for dates that are between the second Sunday in March and the first Sunday in April for the year 2007. Instead of daylight saving time, the time is reported in standard time. For example, for March 30, 2007, the JScript Date object reports time in standard time instead of in daylight saving time.*
Read about it
here.
