According to the link below, these are the dates to note,
http://www.realitysandwich.com/polar_reversals
IMPORTANT DATES TO NOTE:
October 30 to early December 2009 -
I don't recall anything happened that day!!
January 15 to February 15, 2010
June 25 to August 5, 2010
November 1 to December 26, 2010