<P> The dates on which clocks are to be shifted also vary with location and year , consequently , the time differences between regions also vary throughout the year . For example , Central European Time is usually six hours behind North American Eastern Time , except for a few weeks in March and October / November , while the United Kingdom and mainland Chile could be five hours apart during the northern summer , three hours during the southern summer , and four hours a few weeks per year . Since 1996 , European Summer Time has been observed from the last Sunday in March to the last Sunday in October ; previously the rules were not uniform across the European Union . Starting in 2007 , most of the United States and Canada observe DST from the second Sunday in March to the first Sunday in November , almost two - thirds of the year . Moreover , the beginning and ending dates are roughly reversed between the northern and southern hemispheres because spring and autumn are displaced six months . For example , mainland Chile observes DST from the second Saturday in October to the second Saturday in March , with transitions at 24 : 00 local time . In some countries time is governed by regional jurisdictions within the country so that some jurisdictions shift and others do not ; this is currently the case in Australia , Brazil , Canada , Mexico , and the United States . </P>
when does day light savings start and end
from the second Sunday in March to the first Sunday in November