There is an error in the manual. The first date in the example should be November 30, 2010. The full example should read as follows:
For example, in the MY 2011 Breast Cancer Screening measure (which requires 2 years of continuous enrollment), a member who disenrolls on November 30, 2010 (the year prior to the measurement year), and re-enrolls on February 1, 2011 (the measurement year), is considered continuously enrolled as long as there were no other gaps in enrollment during either year. The member has one gap of 31 days (December 1_31) in 2010 and one gap of 31 days (January 1_31) in 2011.
This error will be corrected in the September 2012 release of the MY 2012 manual.