I have been fighting this one for several years. Because of the way the daylight savings start and end time were determined in Israel till not long ago, the operating systems that came out of Microsoft's playground do not contain the settings required for configuring summer clock for Israel. If you are looking for more details, you can take a look at my article for year 2005 at Daniel Petri's website and Daniel's excellent followup in 2006 - both articles were written in order to help system administrators...