Essential Information - Time
Wherever you are in the world, the time on your watch is measured in relation 
to the time at Greenwich in London - Greenwich Mean Time (GMT). British Summer Time, the UK 's form of daylight-saving time, muddies the water so that even London is ahead of GMT from late March to late October.
To give you an idea, San Francisco is usually eight hours and New York five hours behind GMT, while Sydney is 10 hours ahead of GMT. Phone the international operator on 155 to find out the exact difference.
