Reference: www.mypanchang.com
Navaratri: Hawaii and Pacific Time zone (USA/Canada): Oct 15th 2012i, USA/Canada Mountain time and Central time zone: October 15th 2012, USA/Canada Eastern Timezone: October 15, 2012. (Certain cities have prathama as a kshya tithi and hence navaratri to start on Oct 15th. Please check Certain cities in the east coast of the USA have navaratri as a kshya tithi and hence for them navaratri will start from Oct 15th.. Those cities are New york, Boston,etc.. please check
http://www.mypanchang.com/panchangam2012.php to check if your city has prathama kshaya or not) Europe, India, Africa, Malaysia, Australia, Fiji, Newzeland: October 16 2012.
Durga Asthami: Entire world except Hawaii: October 22nd 2012
Dussera: USA/Canada: October 23rd 2012. UK, India, Africa and rest of world October 24th 2012