Daylight savings starts at different times all over the world, however since most of the visitors are from the US I’ll give you those dates first. Daylight savings 2012 in the US starts March 11. at 2am and lasts until November 4. at 2am.
Daylight savings is happening in all of the US except Arizona and Hawai. You move your clock one hour ahead of time in spring, when daylight savings time starts that is, and one hour back in the fall. When it comes to daylight savings time in other parts of the world I will get back to that.